Preheat your oven to 375 degrees and spray a 9x13 casserole dish with non-stick cooking spray.
Make the biscuit layer. Prepare the biscuit mix in a large bowl by combining the mix with water and ½ cup colby jack cheese. Spread this mixture evenly on the bottom of the casserole dish. Bake uncovered for 10 minutes or until the edges start to turn golden in color.
Prepare the meat layer. While the biscuit layer is baking, heat a large skillet over medium-high heat and melt the butter. Sauté the onions in the butter until translucent. Add the garlic and ground beef, then brown the ground beef by flipping and breaking it up as it cooks.
Add flavors. Once the ground beef is cooked, add the salsa and taco seasoning. Stir it together and remove it from the heat. Add the ground beef over the cooked biscuit layer and smooth it out to the sides. Set it aside.
Make the creaming topping. Make the topping by combining the mayonnaise and sour cream with the flavor packet from the biscuit package. Mix it well and then smooth it over the top of the ground beef. Sprinkle the remaining cheese over the top of the casserole.
Bake uncovered for 30-35 minutes or until bubbly.
Serve. Remove from the oven, garnish with parsley, and enjoy!