I’m of no use for the cookbook recommendation but wanted to mention that sodium is the big dietary no-no for hypertension. You probably already heard that though.

I'd sign up for the "Eating Well" or "Cooking Light" magazine or menu web sites, they have menu plans for various dietary preferences. Vegetarian cooking is so diverse, I'd be hard pressed to name a comprehensive beginner cookbook for a non crunchy type of person. You might be better off with something from the "heart healthy" realm, which would have lots of vegetarian options . . . try out at the library first too . . .

If I was making a switch, I'd try gradual, and start by familiarizing myself with whole grain and bean recipes. Heart healthy vegetarianism is founded on those principles. An oldie but goodie is "Diet for a Small Planet" by Frances Moore Lappe, and "Recipes for a Small Planet" by the same author. And cookbooks labeled "Whole Foods" such as the one by Nikki and David Goldbeck, etc. Lots of tried and true versions there.

There are a whole slew of "Moosewood" cookbooks which are not full of simple recipes, but they do have one big positive, in that they include extensive menu pairings/suggestions at the end of each recipe. You might seek out "Moosewood Restaurant Cooks at Home." I have their soups and salad one, called "Moosewood Restaurant Daily Special", it's OK, and also their "Lowfat Favorites" one which is "meh." They do have an extensive selection of options, that's for sure.

ETA that my main beef with Moosewood is that there is just so much to wade through, and most recipes have a fairly long list of ingredients, but if you know your way around the kitchen you can usually adapt to make them much simpler and they do give you an extensive idea of how to pair vegetarian foods to make a meal. In that way at the very least they are a big plus. And they do have great recipes too, just a huge number of options. Which could be good or bad depending on how bad your ADHD is . . . (joking!!)

ETA again--can one really have a "main beef" with a vegetarian cookbook?! :)

I am also always looking for the same, Running. Bith DD’s are vegetarian.

I love SimplyRecipes.com. IME their recipes are reliable. They have a lot of vegetarian recipes. https://www.simplyrecipes.com/search?q=Vegetarian

Same with LeitesCulinaria.com. Reliable recipes pulled from various cookbooks. https://leitesculinaria.com/?s=&f%5Bdiet%5D%5B0%5D=55

If you really want to take a deep dive into vegetarianism and vegetarian cooking and lifestyle, and old classic is "Laurel's Kitchen" by Laurel Robertson, Carol Flinders, Bronwen Godfrey, and George M. Briggs. It's text dense and includes a lot about whole foods cooking and ways of eating that are comparatively simple and easy on the planet, albeit quite a different paradigm from the standard American diet. These authors wrote quite a bit during the 1980's. I like the older books because as I mentioned, they are text dense so go into a lot of the cooking details and nutrition. But you have to want that, otherwise the text is just wasted space . . .

I love the Moosewood cookbooks.

Not a cookbook, but the site Ranchogordo.com has some good recipes for their heirloom beans, which are delicious and taste NOTHING like supermarket beans.

The older cookbook Fagioli: The Bean Cuisine of Italy is available on Amazon. And Williams Sonoma had a popular cookbook called Salad of the Day, a calendar type of 365 salads. They aren't strictly vegetarian but could probably be adapted using an alternate protein like tofu or beans or cheese.

Kswl reminded me of one of my favorite local resources, the Randall's beans web site. Great recipes and menu ideas. Great beans too if you can find them!

https://randallbeans.com/recipes/

I make many recipes from The PlantPure Nation cookbook by Kim Campbell. I bought it years ago after hearing her speak. The only new-to-me ingredient was Nutrional Yeast flakes, which add a cheesey flavor, and that was easily found at my grocery store so its not too odd.

ETA: some of my repeat recipes are Sweet pepper coconut corn chowder, minestrone, creamy African stew, Ethiopian stew, black bean enchiladas (I do use real cheese on these because, come on, enchiladas!).

Rancho Gordo puts up recipes on their IG. They are a treasure.

Another rec of The Moosewood Cookbook. It' a classic and has a number of tasty recipes I use often, even tho we are not vegetarians.

Mollie Katzen has a website where you can find many of her recipes to try out.

https://molliekatzen.com/

Try Mark Bittman's How to Cook Everything: Vegetarian There is a 2017 revised edition with new content, including more vegan recipes. It is designed to be simple(r) and comprehensive. .

Couple of thoughts:

1) before investing in a cookbook, visit the cookbook section of your local library. Honestly, every time I go to the library I check out 1 or 2 cookbooks just for reading. I may or may not make something from the books verbatim or a riff or something.

2) 'expanding plant based menus' and 'vegetarian' are not the same thing. Think about the meals you have that you enjoy and figure out (or ask for help) figuring out how to make more of them.

For example, we love 'bowls'. DS1 worked at a restaurant in high school that made 'kimchi quinoa bowl with jerk tofu' . so i figured out how to make it. One of DH's favorite meals is Pasta with sausage and broccoli rabe. At home he gets a soft polenta bowl, with garlicky roasted broccoli and sundried tomato pesto and a dollop of ricotta. Last night we had cilantro-lime rice, with refried beans, a small piece of chili dusted sockeye and a mango serrano salsa.

We watched a Netflix show the other night called The Game Changers. Jackie Chan, Arnold...you know....people who have to eat right for their careers. ♥ They said the Roman athletes ate Barley & Beans to stay in shape. No meat! They have recipes on the site...ALL Vegan.

Recipes: ALL plant based Take a look.

Add me to the list of Moosewood fans. I also like their recipes because they are old school. Sometimes I read a recipe (usually online) by someone under 30 and they are all over "discovering" some technique that I thought was common sense in the kitchen. It makes me worried about following recipes from some of them.

I know you didn't ask for advice about the blood pressure, but there seem to be lots of stuff out there about flax having more of an effect than some medications. I also didn't discover that there is such a thing as vascular dementia until it was too late for my mom, so good for you for taking this seriously now.

Bittman's How to Cook Everything Vegetarian and the Moosewood books have already been mentioned. The other I would add is Deborah Madison's Vegetarian Cooking for Everyone. Those are the main vegetarian books in my library. Indian recipes skew heavily towards vegetarian or at least reduced emphasis on meats - my son and his GF have been enjoying 660 Curries after watching a couple fo cooking classes by the author on Bluprint (now Craftsy).

Besides vegetarian books, I would also consider options that spread the meat you do eat further. That can be rice, noodle or grain bowls like localeater suggested, but also soups (vegetarian or just heavy on the veggies), stir-frys and salads as the weather warms. Consider expanding the idea of meatless Mondays to M-W-F and then perhaps M-F. Or breakfast, lunch and so many dinners each week. None of the men in my life would be likely to make a total switch, and I don't know that I would, but I have no trouble reducing the meat. Getting complete nutrition from a plant based diet can be challenging, so you may want to consult a nutritionist to help you avoid replacing one problem with another one.

Also consider a farm share. We have a CSA (community supported agriculture) program with a farmer in the area and get a weekly box of vegetables and farm fresh eggs. It forced us to find ways to cook a few things we didn't cook a lot or at all and start looking for new ways to prepare some old standards like broccoli, green beans or summer squash. It's easy when the produce is so fresh and tastes so good. We still buy other produce, but it's fun to discover new things and to meet the challenge of using what the land provides when it provides it. A sense of adventure may lead to more success than one of punishment. Good luck with finding the best changes for you and your DH.

Wow, thank you all! Lots of great suggestions and also a good thought reminder about what exactly I'm trying to do, which is, as several folks pointed out, change up our diet to be less meat based. My goal isn't to transition to a fully vegetarian diet. But we already eat a lot of meals that can easily shift toward meat becoming an enhancement rather than a main portion.

And yes, salt is a huge factor. During the pandemic my husband rather inexplicably changed his lunch staple menu to a sandwich made with processed deli meat (YUCK) and a side of chips (DOUBLE YUCK). I've told him that stuff isn't healthy but as often happens it took a doctor and a sudden marker change (higher BP) to make the point to him.

Anyway, with much appreciation to this wonderful group. I'm off to the library website to check out a Moosewood book ;)

I'm on that same journey, trying to stick to low salt options and lower cholesterol options. That's why I mentioned "beans and grains" because if you become a "vegetarian" and still eat all kinds of dairy and eggs, you're not really lowering saturated fats . . . sigh. That's why I started eating some meat again because I realized from both a health and environmental perspective, (even an animal care perspective) there really wasn't much difference between eating a diet with a lot of dairy and eggs and one with meat, and in some cases, the meat options were healthier . . . but I still then try to eat "vegan" and fiber rich meals because those are the best for heart health. It's more of a struggle in the winter and early spring . . .

Speaking of that, and speaking of CSA's, my best friends joined one near there summer cottage many years ago, and I got them a fresh produce cookbook to help them come up with creative ways to use all the produce. When CSA's first started, I noticed there was a glut of vegetable/farm market cookbooks coming out. I looked through quite a few, which you can probably still find at the aforementioned library!! Here's the one I bought, I am a fan of Andrea Chessman, her recipes are always very practical. I don't think she is active anymore, most of her books are out of print but worth seeking out IMHO. My late Mother got me a vegetable cookbook from Williams and Sonoma one year for Christmas. The recipes are pretty good but the big appeal is the sexy inspirational photographs of each dish. You might look for something like that to up your kitchen mojo, although such things can be found now online in blogs. But lots of times I don't really want to spend my time in front of a computer screen.

Garden Fresh Vegetable Cookbook by Andrea Chessman.

More of her work, lots of cool cookbooks, including one featuring just beans and grains. https://www.amazon.com/Andrea-Chesman/e/B001HPC4O2/ref=dp_byline_cont_pop_book_1

I have been a vegetarian for 28 years so I'm very familiar with cooking without meat. I haven't been cooking from cookbooks nearly as much lately. There are just so many wonderful recipes online. I keep an iPad in the kitchen for recipes.

https://cookieandkate.com (from author of book recommendation by @lisaam)

https://www.loveandlemons.com (the author has a few cookbooks)

https://www.feastingathome.com/recipes/?fwp_featured=vegetarian-vegan-mains%2Cdetox

https://www.101cookbooks.com (the author has a cookbook as well)

I do have an assortment of cookbooks as well. These are probably the ones I use the most.

Moosewood Simple Suppers

The Greens Cookbook

Vegetarian Cooking for Everyone (Deborah Madison)

These are some of the cookbooks on my list to buy, but I just haven't (yet) pulled the trigger.

Love Real Food by Kathryne Taylor

Love and Lemons Every Day by Jeanine Donofrio

Vegan Richa's Indian Kitchen by Richa Hingle

Super Natural Every Day by Heidi Swanson

If you don't already have a multi-cooker, I highly recommend them. If you want to switch to eating more whole grains they are fab for that. Ours is Cuisinart. Here's a cookbook that might be on my list soon, The Ultimate Rice Cooker Cookbook: 250 No-Fail Recipes for Pilafs, Risottos, Polenta, Chilis, Soups, Porridges, Puddings, and More, from Start to Finish in Your Rice Cooker.

Its by Beth Hensperger. I have her bread machine cookbook, which has 365 recipes. Not everyone is a winner but it's been fun to figure out which ones we like from the diverse assortment!

Oh @carolb_w_fl_coastal_9b thank you for the link to the Mollie Katzen site! Fantastic!