Preheat oven to 350°F and lightly grease a 9x13-inch baking dish.
Brown the sausage in a skillet until fully cooked.
Add butter and flour to create a roux; stir for 1 minute.
Gradually whisk in milk until a thick, creamy gravy forms; season with salt and pepper.
Cut biscuits into quarters and spread half on the bottom of the baking dish.
Pour the sausage gravy evenly over the biscuits.
Whisk eggs, milk, and seasonings, then pour over the gravy layer.
Top with shredded cheddar and remaining biscuit pieces.
Bake for 35–45 minutes until biscuits are golden and cooked through.
Let rest 10 minutes before serving.