Step 1

Preheat oven to 350°F.

Step 2

Place butter in the bottom of a 9x13-inch baking dish. Place dish in oven until butter is melted, then remove.

Step 3

Meanwhile, whisk together the milk and baking mix in a large bowl. Set aside.

Step 4

In a separate bowl, whisk together the chicken stock and soup. Set aside.

Step 5

Arrange the casserole in the following layers, but do not stir.

Step 6

First, arrange chicken evenly over the melted butter. Arrange vegetables evenly over the chicken, followed by the onion.

Step 7

Sprinkle cheese evenly over the onion, then pour the Bisquick batter evenly over the top. Pour the soup-stock mixture over the Bisquick.

Step 8

Bake until top is beginning to brown, 45-50 minutes. Let rest 10 minutes before serving. Enjoy!