Preheat oven to 375ยบ. Line a baking sheet with parchment paper and spray with cooking spray. Place ½ cup mounds of cheddar on baking sheet and season with pepper.
Bake until cheese is melty and slightly crispy, 5 to 7 minutes. Blot grease with a paper towel.
Meanwhile, set up 4 stations of two upside-down glasses and a wooden spoon as a bridge. Using a spatula, immediately transfer cheese mounds to wooden spoons to form shells. Let cool.
Meanwhile, make taco meat: In a large skillet over medium heat, heat oil. Add onions and cook until soft, 5 minutes, then add ground beef and cook until no longer pink, 6 minutes more. Drain fat and season with taco seasoning.
Assemble tacos: Place beef in shells and top with lettuce, tomatoes, and hot sauce.
Recipe by 5* trending recipes with videos at https://food.theffeed.com/2019/05/03/cheese-taco-shells/