I have a breakfast mixture leftover from making breakfast burritos the other day. It has cooked scrambled eggs, sausage, bacon, onion & peppers. I cooked it all and made the burritos. The leftovers I put in a freezer baggie and put in the freezer. Can I add bisquick mix to this and bake it to make a breakfast casserole? My main concern is the eggs since they are already cooked. 
If had that mix (cooked scrambled eggs, sausage, bacon, onion & peppers), then I would make a breakfast pot pie like this Hearty Chicken Pot Pie. I would butter the casserole dish and then layer like this.    The first layer would be the scrambled eggs, onions and peppers and sausage. Next layer would be some shredded cheddar. Now make Bisquick and pour on top Lastly, I'd lay bacon over the dough   Bake it until golden brown and delicious. Since everything is really cooked safely, you are just setting the dough crust. I think you'd want to keep the crust thin and avoid a lot of dough. 