Tonight I just experimented in making a casserole, not measuring terribly carefully, and it turned out to be tremendous. I was not expecting that. So I will give you my approximations for measurements but I don't think it matters all that much. Aren't casseroles really just about throwing things you like, that go together, in a dish and baking it? Also, in case you haven't noticed I really love mushrooms and onions. Like, a lot.
P.S. I'm noticing a pattern in my foods looking not so attractive but they taste so good.
Chopped Onions - approx 1/3 cup
Portobello Mushroom Slices - approx 1 cup
Tofu - approx 1/4 block
Nutritional Yeast - as much as you'd like, I used probably about 2 Tbsp
Vegan Cheddar Cheese - I used approx 1.5 oz Daiya
Dash of Salt for flavor
Seasoned Packaged Tofu Meat substitute - I used Field Roast Tomato Flavor slices (2) but it would work well with any "deli" slices, fakin bacon, or soysage just for a little flavor.
In frying pan with either nonstick spray or oil, saute the onions. After a few minutes add in the mushrooms and saute for a few more minutes. Crumble the tofu and toss into the pan along with the nutritional yeast, salt, and meat substitute. Saute for another minute or two. Toss in the vegan cheese, stir in quickly and move it right to the casserole dish. Sprinkle some vegan cheese on top if you like. Bake at 400 degrees Fahrenheit for about 15 minutes.