Preheat oven to 350°F and lightly grease a 9x13-inch pan with non-stick spray.

In a large pan or skillet over medium-high heat, cook ground beef, onion, and red bell pepper until meat is browned and veggies are softened. Drain off grease and set aside.

Stir in taco seasoning packet, salt, and pepper to taste.

In a medium bowl, whisk together sour cream, mayonnaise, 1 cup cheddar cheese, green chiles, and garlic powder.

In a separate bowl, combine biscuit mix with 1 cup water (adding a little more water as needed) until a soft dough forms.

Press dough into the bottom of greased baking dish, then bake for 5-7 minutes, or until lightly golden.

Remove baking dish from oven and spread beef mixture over biscuit layer, then top with diced tomatoes.

Spread sour cream mixture over tomatoes, then cover with remaining cheddar cheese.

Return baking dish to oven and cook for 30 minutes, or until warmed through.

Remove from oven, serve, and enjoy.