Step 1: Cook the pasta shells until they have an al dente texture (a little bit of firmness to the pasta).
Step 2: Make the taco meat. Sauté the beef, onion, bell pepper, and garlic until the beef has browned and the veggies are soft. Add tomatoes, taco seasoning, and water. Simmer until thickened.
Step 3: Preheat your oven to 350°F (175°C).
Step 4: Spread 1/2 cup of salsa in the bottom of a casserole dish. Spoon taco meat into the shells, and place them into the casserole dish. Spoon the remaining salsa on the taco stuffed shells. Sprinkle cheese on top.
Step 5: Cover and bake for about 30 minutes.
Serve your Taco Stuffed Shells hot, garnished with your favorite toppings like sour cream, chopped cilantro, or sliced jalapeños.