I do have one, but it is at home and I'm on the road. It was pretty simple though, just seasonings, olive oil and the mushrooms, then whirled in the food processor. I know my fake chopped chicken livers recipe has an egg in it, but I don't think this one does.

Mushroom pate is a new idea for me, so I would start with a recipe from a known site that has good ratings. Not a lot of reviews here, but the’re all 5 stars and the recipe looks good: https://www.eatingwell.com/recipe/253039/mushroom-pate/

This answer is mostly to bump up your thread. I've never heard of "boletus" before, though apparently they grow in California. My experience with mushroom patés is that they're very simple. Some have onion and/or garlic, some have wine, and some don't. My first exposure to fancy cooked mushrooms was Julia Child's quiche, for which creminis are sliced thin and cooked with shallots in port and butter. You sauté them, cover and simmer, then reduce all the liquid (much of it water released by the mushrooms). Amazing. Some patés have very similar flavors. Most I'm familiar with are very simple.

Are you trying to recreate your mom's recipe? Can you remember the flavors? For instance, was there some kind of onion? (shallot, scallion, leek.. many onion-like things to choose from but not all patés have onion-y flavors).

Boletus is Cèpes, if I understand. Here, it's a precious mushroom that's very expensive so I wouldn't be maling it into pâté. This recipe looks tasty. I like the idea of sherry and cream https://www.taste.com.au/recipes/mushroom-pate-2/7a8ada4d-32a7-402d-9df6-96822d29eb2d