Step 1: Prepare the Filling

1. In a large skillet over medium heat, add olive oil or butter.

2. Sauté diced onion until translucent, about 3-4 minutes.

3. Add garlic and cook for 30 seconds until fragrant.

4. Stir in shredded or cubed cooked chicken.

5. Add cream of chicken soup, sour cream, and milk. Mix until smooth and creamy.

6. If using, stir in frozen peas and carrots.

7. Season with salt, pepper, and paprika.

8. Cook for 3–5 minutes until mixture is heated through and slightly thickened.

9. Remove from heat and set aside.

Step 2: Mix the Biscuit Dough

1. In a large bowl, combine flour, baking powder, sugar, salt, garlic powder, and dried parsley.

2. Cut in the cold butter using a pastry cutter or your fingers until mixture resembles coarse crumbs.

3. Stir in shredded cheddar cheese.

4. Pour in cold buttermilk and gently stir until just combined. Do not overmix.

Step 3: Assemble the Casserole

1. Preheat your oven to 375°F (190°C).

2. Grease a 9×13-inch baking dish with butter or non-stick spray.

3. Pour the prepared chicken filling into the dish and spread evenly.

4. Drop spoonfuls of biscuit dough over the filling, slightly flattening each mound to cover more surface area. Leave some gaps for steam to escape.

Step 4: Bake the Casserole

1. Place the casserole in the preheated oven.

2. Bake for 25–30 minutes, or until the biscuit tops are golden brown and the filling is bubbling around the edges.

Step 5: Brush with Garlic Butter

1. While the casserole bakes, prepare the garlic butter topping by mixing melted butter with garlic powder and parsley.

2. Once the casserole is done, immediately brush the tops of the biscuits with garlic butter for that classic Cheddar Bay flavor.

Let the casserole cool for 5–10 minutes before serving.