(Alli says this makes 8 hearty servings, or 10-12 regular servings. Let's get started with these ingredients.)
1 lb. pork breakfast sausage
2 cups half and half, divided use
2 tsp. all-purpose flour
1 tsp. each kosher salt and freshly ground black pepper
10 frozen buttermilk biscuits, partially thawed, cut in half, and
1 1/2 cups shredded cheddar cheese
Preheat oven to 375 degrees F. Coat a 9 x 13 baking dish with non-stick spray. Meanwhile, brown sausage in a heavy skillet over medium heat; break into chunks and cook until no longer pink. Set cooked sausage aside to drain on paper towels, reserving drippings in pan for gravy. Whisk flour into 1/4 cup of the half and half until smooth, then pour this mixture into the remainder of the half and half; beat in eggs and add salt and pepper.
Layer 10 biscuit bottoms across prepared baking dish.Sprinkle half of the sausage over the biscuit bottoms, then top sausage with half of the cheese. Repeat layering (except for cheese). Pour egg mixture over top of all; transfer to preheated oven and bake for 30 minutes. Remove from oven and sprinkle remaining cheese over top; bake an additional 10-15 minutes, or until knife inserted into a biscuit comes out clean and center if no longer jiggly. Let casserole stand for 10 minutes before serving.
To make your gravy, melt 3 Tbs. butter in skillet with sausage drippings; add 3 Tbs. all-purpose flour over medium heat; whisk until smooth, cooking about 2 minutes, whisking constantly. Slowly whisk in milk until entire mixture is thickened and smooth, 5-8 minutes. Season gravy to taste with salt, pepper and red pepper flakes, if desired.