Preheat Oven: Preheat your oven to 375°F (190°C) and lightly grease a 9×13 inch baking dish.

Brown Sausage: Brown the sausage in a large skillet over medium-high heat until thoroughly cooked, breaking it up with your spatula as it cooks. Once cooked, transfer the sausage to the prepared baking dish, spreading it out evenly.

Prepare Gravy: In the same skillet, leave about 2 tablespoons of sausage grease. Sprinkle the flour over the grease and whisk it together to form a roux. Cook for about a minute to remove the raw flour taste. Gradually pour in the milk, whisking constantly to prevent lumps from forming. Bring the mixture to a simmer and continue whisking until it thickens to the consistency of gravy.

Season Gravy: Season the gravy with black pepper and salt, stirring well to incorporate the seasonings. Pour the gravy evenly over the sausage in the baking dish.

Prepare Biscuits: Separate the biscuit dough into individual biscuits and cut each biscuit into quarters. Scatter the biscuit pieces over the gravy in the baking dish.

Bake: Place the baking dish in the preheated oven and bake for about 25 minutes or until the biscuits are golden brown. If using cheese, sprinkle it over the top of the casserole during the last 5 minutes of baking.

Serve: Once done, remove the casserole from the oven and let it sit for a few minutes before serving. Optionally, garnish with chopped fresh parsley for a pop of color before serving.