Mix 3 eggs, 1 cup of milk, 3/4 to 1 cup Bisquick and whatever you have leftover in the fridge. (I have used onions, mushrooms, broccoli, tomatoes, garlic, green beans.) Bake at 375 degrees for 35-40 minutes.
I usually mix everything together in my pyrex pie plate and put it in the oven. It's just the right size. The pie comes out a lot like a quiche.
When I have a little bit of this, a little bit of that left over, I just put it together in my pie. It's one of Joe's favorites.