Preheat the Oven

Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish with cooking spray or a light coating of oil.

Cook the Beef and Vegetables

In a large skillet over medium heat, cook the ground beef with diced onion and bell pepper until the beef is browned and the vegetables are soft, about 7-8 minutes. Drain any excess grease, if necessary.

Season the Mixture

Add the taco seasoning, diced tomatoes with green chilies, and salt and pepper to taste. Stir well to combine and let cook for another 2-3 minutes to allow the flavors to meld. Remove from heat and set aside.

Prepare the Sour Cream Mixture

In a mixing bowl, combine the sour cream, mayonnaise, and 1 cup of the shredded cheddar cheese. Mix until smooth.

Layer the Casserole

Spread the biscuit dough evenly across the bottom of the greased baking dish. Add the ground beef mixture over the dough in an even layer. Spoon the sour cream mixture on top of the beef layer, spreading it evenly. Finish by sprinkling the remaining cup of cheddar cheese on top.

Add Tomato Slices

Arrange the sliced tomato over the top of the cheese layer for added color and flavor.

Bake the Casserole

Place the baking dish in the preheated oven and bake for 30-35 minutes, or until the cheese is melted and bubbly and the biscuit base is cooked through.

Garnish and Serve

Remove from the oven and let the casserole cool for a few minutes before serving. Garnish with chopped parsley or green onions, if desired.