When these guys come out of the oven, it’s game over! Everyone’s trying to snag one before it’s gone

– 1 lb ground beef
– 12 taco shells
– 1 cup shredded cheddar cheese
– 1 packet taco seasoning
– 1/2 cup water
– 1 tomato, diced
– 1/4 cup finely chopped onion
– Optional toppings: sour cream, chopped lettuce, sliced jalapeños, salsa