Preheat your oven to 350°F (175°C). Lightly coat a 9x13-inch baking dish with cooking spray.

In a large skillet over medium heat, add the lean ground beef, yellow onion, and red bell pepper. Cook for 8-10 minutes until browned. Drain excess fat.

In a mixing bowl, combine taco seasoning, water, biscuit mix, sour cream, mayonnaise, and diced green chiles. Mix until smooth.

Transfer half of the beef mixture into the baking dish, followed by half of the biscuit mixture, half of the cheddar cheese, and a drizzle of salsa. Repeat layering.

Cover with aluminum foil and bake for 30-35 minutes, or until heated through and bubbly.

Let the casserole cool for 10 minutes before serving. Slice and garnish as desired.