Step 1

Preheat the oven to 375℉. Grease a 9x9-inch baking dish with non-stick cooking spray. Set aside.

Step 2

In a large skillet, over medium-high heat, cook and crumble the ground beef and finely diced onion until the beef is no longer pink and the onion is translucent, about 8-10 minutes. Drain any excess grease from the pan.

Step 3

Stir in the taco seasoning and diced green chilies until combined. Cook for an additional 2-3 minutes until fragrant.

Step 4

In a small mixing bowl stir together the sour cream, mayonnaise, and 1 cup shredded cheddar cheese until combined.

Step 5

Spread ground beef mixture evenly into the bottom of the prepared baking pan. Evenly spread the sour cream mixture over top the ground beef layer.

Step 6

In a medium bowl, add the dry cheddar bay biscuit mix and water. Stir until a soft dough forms. Drop spoonfuls of the biscuit dough over the sour cream layer, covering as much of the surface as possible.

Step 7

Sprinkle the remaining 1/2 cup shredded cheddar cheese on top of biscuit layer.

Step 8

Bake the casserole for 25-30 minutes or until the biscuit topping is golden brown and cooked through.

Step 9

Remove the casserole from the oven and let it sit for 5-10 minutes before serving.

Step 10

While it's cooling, mix together the melted butter and half of the seasoning packet (from the cheddar bay biscuit mix, or use all of it) until combined, and then use a pastry brush to brush the butter over top the hot biscuit topping.*The seasoning packet is quite salty so I recommend just doing a sprinkling of it or only half of the packet. Depending on flavor preference, use as little or as much as you want. Or omit the seasoning packet and just do the melted butter.