Chicken and biscuit bake tops a creamy chicken and vegetable filling with fluffy golden biscuits. This protein-packed family casserole is comfort food at its best and comes together quickly.
Preheat your oven to 400°F (205°C) with a rack in the center position.
In a large skillet, melt butter over medium heat. Add diced onion and sauté for 3–4 minutes until softened but not browned.
Sprinkle flour into the skillet and stir continuously for 1 minute, ensuring flour is fully incorporated and no lumps remain.
Gradually whisk in milk and chicken broth, raising heat to medium-high. Cook, stirring, until thickened and bubbly (2–3 minutes).
Add shredded chicken, mixed vegetables, salt, pepper, thyme, and garlic powder. Stir well and let the filling simmer at low heat for 3 minutes so flavors meld.
Pour the hot filling into a greased 9x13-inch baking dish, spreading evenly to the corners.
Arrange biscuit dough pieces on top of the filling, spacing evenly. Brush biscuit tops lightly with melted butter if desired.
Bake for 25–28 minutes, until biscuits are deeply golden and baked through, and filling is bubbling around the edges.
If biscuit tops brown too quickly, tent loosely with foil for the last 10 minutes of baking.
Allow the casserole to rest for 5 minutes before serving to let the filling set slightly.