01 -
Heat your oven up to 350°F (175°C) and let it get hot while you get everything else ready.
02 -
Toss your thin onion slices into a medium skillet with some bacon grease and cook on medium till they're soft and brown, around 10 minutes. Let them cool down for a bit.
03 -
Start with half the onions in your pie crust, cover that with half the tomatoes, then sprinkle on half the bacon. Go again with the rest of the onions, tomatoes, and bacon to finish the layers.
04 -
Mix the mozzarella, mayo, sour cream, flour, garlic powder, pepper, and salt together in a bowl till it all comes together.
05 -
Smooth the cheesy mix right over everything else in the dish. Pop the whole thing onto a baking sheet and bake for 35 to 40 minutes or until that top is bubbly and nice and golden.
06 -
Take it out of the oven and give it a few minutes to chill. If you want, sprinkle with fresh parsley or chives before you cut into it.