Bake 1 package (8 count) buttermilk biscuits according to the package instructions.
While the biscuits are baking, brown 1 pound breakfast sausage in a large skillet with deep sides over medium-high heat, breaking up the sausage as it cooks. Do not drain the grease.
Reduce the heat to medium-low and add 1 tablespoon butter to the skillet. Stir until melted.
Sprinkle ¼ cup all-purpose flour over the sausage and stir until the sausage is evenly coated. Cook for approximately 1 minute.
Slowly pour in 2½ cups whole milk while stirring continuously.
Simmer the mixture over low heat for 3-5 minutes, stirring frequently and scraping the bottom and sides of the skillet, until the gravy thickens.
Season the gravy with 1 teaspoon black pepper and ½ teaspoon salt. Stir to combine.
Split the warm biscuits and serve the hot sausage gravy over the top.
Serve immediately and enjoy.
Notes
Refrigerate the leftovers in an airtight container for up to 1 week.