Preheat the oven to 400°F.
Bake the biscuits according to the package instructions.
While the biscuits are baking, cook the breakfast sausage in a large skillet over medium heat until browned and cooked through.
Sprinkle the flour over the sausage and stir to combine.
Gradually pour in the milk, stirring constantly, until the mixture thickens and comes to a simmer.
Reduce the heat to low and let the gravy simmer for 5-10 minutes, stirring occasionally, until it reaches your desired consistency.
Season the gravy with salt and pepper to taste.
Split the biscuits in half and place them on plates.
Spoon the gravy over the biscuits and serve hot.