01 - 
                Preheat oven to 400º F and lightly grease a 9x13-inch baking dish with non-stick spray.
              
              
              
                02 - 
                In a large bowl, beat eggs and milk together until combined. Stir in biscuit mix, and add kosher salt and freshly ground pepper, if desired. Set aside.
              
              
              
                03 - 
                Season ground beef with salt and pepper, then cook in a skillet over medium heat until browned. Drain excess fat and stir in taco seasoning.
              
              
              
                04 - 
                Place cooked beef in an even layer in the greased baking dish. Spread the prepared biscuit mix in an even layer on top of the beef.
              
              
              
                05 - 
                Transfer the baking dish to the oven and bake for 22-25 minutes, or until the biscuit layer is golden brown.
              
              
              
                06 - 
                Remove the casserole from the oven and let it cool for 10 minutes. Spread the sour cream evenly on top of the biscuit layer.
              
              
              
                07 - 
                Top with chopped lettuce, tomatoes, and olives, if using. Sprinkle grated sharp cheddar cheese on top.
              
              
              
                08 - 
                Serve the taco casserole hot and enjoy!