Step 1

Cook the pasta to al dente according to the package directions. Drain well.

Step 2

Preheat the oven to 375F. Spray the inside of a 9x13-inch casserole dish with nonstick spray.

Step 3

Add the beef, onion, bell pepper, and garlic to a large skillet over medium-high to high heat. Cook until the meat is browned, about 5 minutes, stirring occasionally to break up the meat.

Step 4

Stir in the diced tomatoes (with juices), taco seasoning, and water. Cook uncovered until the mixture is thickened, about 10 minutes, stirring occasionally. Cool slightly until the meat isn’t too hot to touch.

Step 5

Spread half of the salsa in the bottom of the prepared casserole dish.

Step 6

Spoon the meat mixture into the cooked pasta shells and arrange them in the prepared casserole dish. Spoon on the remaining salsa. Sprinkle the cheese on top.

Step 7

Cover the dish with foil and bake until the shells are warm throughout and the cheese is melted, about 20 minutes. If you want to brown the top a little, remove the foil and broil for a couple minutes.

Step 8

Serve warm with desired toppings.