FL --- The mushroom is the crust? Sounds good! Did you come up with the recipe yourself? I've never had mushrooms off of a pellet grill before (hints towards BPS Team)... how do they hold up as a crust?
Tofu marinated in teriyaki and EVOO then grilled on a pellet pit is a darn fine alternative to meat! Sesame oil, soy and rice vinegar is another great marinade for tofu
Use grill grates on sliced zucchini. Bell Peppers Portabella Mushrooms slices etc. Remember they will only eat food off a grill that has not had meat cooked on it or has been clean to the natural metal like in a self cleaning oven.
I was a vegetarian for nine months one time and then another time a vegan for six months. Not for any silly political reasons but to help lower cholesterol and other levels. The levels dropped but not that much and my constant drooling for animal protein won out both times. A few times friends made me Portabella mushroom hamburgers by sauteing the mushroom for quite a while, adding wine and garlic and pressing it down to release liquid until YUM, with all the fixings you would normally put on a burger they were fab. I have many Vegetarian and vegan cookbooks and recipes that are pretty good.