Preheat your oven to 350°F (175°C).

In a large skillet over medium heat, brown the ground beef with chopped yellow onion and red bell pepper for 7-10 minutes. Drain excess fat and add taco seasoning.

In a mixing bowl, combine the biscuit mix with water until slightly lumpy. Do not overwork the dough.

Spray a casserole dish with cooking spray. Spread half of the biscuit mixture in the dish, then layer with the beef and vegetable mixture.

Mix together sour cream, mayonnaise, and diced green chiles. Spread this creamy filling over the beef layer.

Dollop remaining biscuit mixture over the creamy filling and smooth it out. Top with shredded cheddar cheese.

Bake for 25-30 minutes until golden brown and bubbly.

Let the casserole cool for about 10 minutes before serving.