1-First Step: Preheat and Prepare Baking Dish
Preheat your oven to 350°F (175°C) and lightly grease a 13×9-inch (33×23 cm) baking dish to prevent sticking. This ensures even baking and easy cleanup.

2-Second Step: Brown the Sausage
In a skillet over medium-high heat, cook the sausage, breaking it into small pieces, until fully browned and cooked through. Drain any excess fat if desired. If using turkey sausage, you might add 2 to 3 tablespoons of butter later to enrich the gravy.

3-Third Step: Prepare Biscuit Base
Cut the biscuit dough into 1-inch pieces or quarters (depending on biscuit size). Arrange these pieces evenly in the prepared baking dish as the casserole base.

4-Fourth Step: Layer Sausage and Cheese
Spread the cooked sausage evenly over the biscuit pieces. Sprinkle shredded cheese uniformly across the sausage layer for melty richness.

5-Fifth Step: Mix Eggs and Milk, then Pour
In a bowl, whisk together the 6 eggs, ½ cup of milk, salt, and pepper. Pour this mixture evenly over the layered biscuits, sausage, and cheese to blend flavors and help bind the casserole.

6-Sixth Step: Prepare Sausage Gravy
Prepare the sausage gravy according to the package instructions for the gravy mix. Alternatively, make homemade sausage gravy by melting butter in the sausage skillet, whisking in flour, then gradually adding milk and cooking until thickened, combined with cooked sausage. Pour the creamy gravy evenly over the entire casserole.

7-Final Step: Bake and Serve
Bake uncovered in the preheated oven for 35 to 45 minutes, or until the eggs are set and biscuits are fully cooked and golden. To prevent over-browning, cover loosely with foil during the last 10 to 15 minutes if needed. Let the casserole rest for a few minutes before serving warm. Adjust cooking times and ingredients to fit dietary needs, such as vegan or gluten-free options.