Biscuit-topped chicken pot pie casserole features a creamy chicken and vegetable filling under fluffy golden biscuits. This protein-packed family comfort food is easier than traditional pot pie and just as satisfying.
Preheat the oven to 400°F and grease a 9x13-inch casserole dish.
Heat butter in a large skillet over medium heat; sauté the diced onion until translucent, around 4 minutes.
Add flour and stir constantly for 2 minutes to cook out the flour taste, then gradually whisk in chicken broth and milk to form a smooth sauce.
Stir in chicken, mixed vegetables, salt, pepper, thyme, and garlic powder; simmer for 5–6 minutes until thick and bubbling.
Transfer the filling to the prepared casserole dish and evenly top with the biscuit dough pieces.
Bake uncovered for 22–25 minutes until the biscuits are golden and cooked through; cool for 5 minutes before serving.