These are both delicious, I love potato casseroles! you could double or triple to feed 20 people. SCALLOPED POTATOES WITH THREE CHEESES 3/4 cup (packed) grated extra-sharp cheddar cheese (about 4 ounces) 3/4 cup crumbled Danish blue cheese (about 4 ounces) 1/3 cup (packed) freshly grated Parmesan (about 1 1/4 ounces) 4 pounds russet potatoes, peeled, cut into 1/4-inch-thick rounds 1 1/2 teaspoons salt 1/2 teaspoon ground black pepper 1/4 cup finely chopped onion 3 tablespoons all purpose flour 4 tablespoons (§ stick) butter 3 cups whole milk Preheat oven to 400°F. Lightly butter 13x9x2-inch glass baking dish. Mix cheddar cheese, blue cheese and Parmesan in small bowl. Arrange half of potatoes in prepared baking dish, overlapping slightly. Sprinkle with teaspoon salt and 1/4 teaspoon pepper. Sprinkle onion over, then flour. Dot with 2 tablespoons butter. Sprinkle half of cheese mixture over. Top with remaining potatoes, 3/4 teaspoon salt, 1/4 teaspoon pepper and 2 tablespoons butter. Reserve remaining cheese. Bring milk to simmer in medium saucepan. Pour milk over potatoes (milk will not cover potatoes completely). Cover baking dish tightly with foil. Bake 45 minutes. Uncover dish (liquids in dish may look curdled); sprinkle potatoes with reserved cheese mixture. Bake uncovered until potatoes are tender and cheese is deep golden brown, about 45 minutes longer. (Can be prepared 2 hours ahead. Let stand at room temperature. Cover and rewarm in 375°F oven about 20 minutes.) Remove from oven; let stand 15 minutes before serving. Makes 12 servings. Bon Appétit November 1999 Rick Rodgers Epicurious.com © CondéNet, Inc. All rights reserved. My notes: I used Gruyere in place of blue chees and it was delish. Potato Gratin From Weight Watchers Easy Weeknight Favorites 1 garlic clove, halved Cooking Spray 1 c chopped onion 6 medium size baking potatoes, peeled and cut into thin slices 1/4 tsp salt 1/4 tsp freshly ground black pepper 3/4 c shredded extra sharp cheddar cheese 1/4 c grated romano cheese 1\-3/4 c chicken broth 1 c evaporated milk Preheat oven to 425F.Rub a shallow 3 quart baking dish with cut sides of garlic halves, discard garlic. Coat dish with cooking spray Coat non\-stick skillet with cooking spray, place over medium heat until hot. Add onion, sauté 5 minutes or until tender; set aside. Arrange one third of potato slices in prepared dish, sprinkle with half of the salt and half of the pepper. Top with half of the sautéed onions and half of the cheddar and romano cheeses. Repeat layers, ending with the remaining potato slices. Bring broth and milk to a boil over low heat in a small saucepan. Pour over potato mixture. Bake uncovered, at 425F for 50 minutes or until tender and golden brown. Let stand 5 minutes before serving. Yield: 6 servings Linda

Clair, Once the potatoes have cooked in the cream and started to thickened, they get poured into a butter casserole and are finished in the oven. Potato Gratin I don't usually follow a recipe when making a Potato Gratin. Use the following as a guideline and adjust everything to your own taste. For a rich dish, use butter and whipping cream. 3 to 5 Russet Potatoes (or more depending on number of servings required) 1 garlic clove 1 teaspoon fresh thyme (optional) Butter Heavy Cream (or milk if you want a less rich version) Parmesan cheese Gruyere cheese as well as cheddar and blue cheeses can be added for a different taste all together. Salt and pepper Rub cut garlic clove over the surface of a gratin or casserole dish. Butter. Slice potatoes and place in pot and add enough cream/milk to almost cover. Add the garlic clove, thyme, salt and pepper. Bring to a boil and simmer for a few minutes, stirring often so the potatoes do not stick. When the potatoes have released some of their starch and thickend the liquid, remove the garlic clove, add 1 to 2 tablespoons butter and some grated Parmesan cheese. Pour into prepared casserole dish, dot with butter and sprinkle with some more Parmesan cheese. TIP: If you like a more garlicky flavour, just grated a garlic clove on a microplane and add to the cream mixture. Bake in a 375ðF oven for 45 to 55 minutes or until potatoes are tender. Remove from oven and let sit for 10 minutes before serving. Another way to make a potato Gratin is to saute some thinly sliced onions in olive oil or butter until golden, add some thyme, and some chicken broth. Add the potatoes, salt and pepper and bring to a boil. Pour into a buttered casserole dish sprinkle with some Parmesan cheese and bake until cooked.

I like cheese in my scalloped potatoes. These are my two "go to" recipes. Potato Gratin Yield: 6 servings (serving size: 1 cup) 1 clove garlic, halved Cooking Spray 1 c onion, chopped 6 medium sized baking potatoes, peeled and cut into 1/8 inch slices 1/4 tsp salt 1/4 tsp pepper 3/4 c extra sharp cheddar, grated 1/4 c romano cheese, grated 1-3/4 c chicken broth 1 c evaporated milk Preheat oven to 425 Rub a shallow 3 qt casserole with cut sides of garlic halves, discard garlic. Coat dish with cooking spray. Coat a non-stick skillet with cooking spray, place over medium heat until hot. Add Onion and saut� 5 minutes or until tender., set aside. Arrange 1/3 of potato slices in prepared casserole, sprinkle with half the salt and half of the pepper. Top with half of the onions and half of the cheeses. Repeat layers, ending with potato slices. Bring broth and milk to a boil over low heat in a small saucepan. Pour over potatoes. Bake, uncovered for 50 minutes or until potatoes are tender. Let stand 5 minutes before serving. Scalloped Potatoes with Three Cheeses Bon App�tit : November 1999 by Rick Rodgers Ingredients 3/4 cup (packed) grated extra\-sharp cheddar cheese (about 4 ounces) 3/4 cup crumbled Danish blue cheese (about 4 ounces) 1/3 cup (packed) freshly grated Parmesan (about 1 1/4 ounces) 4 pounds russet potatoes, peeled, cut into 1/4\-inch\-thick rounds 1 1/2 teaspoons salt 1/2 teaspoon ground black pepper 1/4 cup finely chopped onion 3 tablespoons all purpose flour 4 tablespoons (1/2 stick) butter 3 cups whole milk Preparation Preheat oven to 400�F. Lightly butter 13x9x2\-inch glass baking dish. Mix cheddar cheese, blue cheese and Parmesan in small bowl. Arrange half of potatoes in prepared baking dish, overlapping slightly. Sprinkle with teaspoon salt and 1/4 teaspoon pepper. Sprinkle onion over, then flour. Dot with 2 tablespoons butter. Sprinkle half of cheese mixture over. Top with remaining potatoes, 3/4 teaspoon salt, 1/4 teaspoon pepper and 2 tablespoons butter. Reserve remaining cheese. Bring milk to simmer in medium saucepan. Pour milk over potatoes (milk will not cover potatoes completely). Cover baking dish tightly with foil. Bake 45 minutes. Uncover dish (liquids in dish may look curdled); sprinkle potatoes with reserved cheese mixture. Bake uncovered until potatoes are tender and cheese is deep golden brown, about 45 minutes longer. (Can be prepared 2 hours ahead. Let stand at room temperature. Cover and rewarm in 375�F oven about 20 minutes.) Remove from oven; let stand 15 minutes before serving. My notes: I use gruyere in place of blue cheese and this was delicious! Linda

My favorite au gratin recipe is linked below. You'll see some reviews stating that it's soupy, but you have to whisk the roux and milk until thickened before pouring over the potatoes. It's decadent, so I only make it for special occasions ;) The sauce is wonderful over vegetables, too. I've been reading Chowhound in concert with this board and someone over there asked about a Tian. Would work for vegan, without the cheese, and vegetarian alike. Tian Here is a link that might be useful: Au Gratin Potatoes on food.com