Cook the sausage in a skillet and set aside. Then cook the bacon in the skillet and save 1 tablespoon of the bacon grease. Add the bacon grease to a large skillet set over medium heat. Add the onion and bell peppers, and stir to combine.
In a large bowl, whisk the eggs with the half and half, salt, and pepper. Pour the mixture all over the top of the casserole. Gently press down on the top of the casserole so the bread starts soaking in the egg mixture.
Bake for 40 minutes or until a toothpick comes out clean with no wet egg in the center. You may need to cover the casserole with foil if it starts browning too much. Allow it to sit for 10 minutes before slicing and serving.