Cook the pasta shells according to package directions. Let cool and set aside.
In a large saucepan, brown the ground beef in the oil over medium heat for 3 minutes, stirring occasionally.
Add the taco spice mix and onion, cook while stirring for 3 minutes. Turn the heat down to medium-low, add the water, stir and cook for another 5 minutes.
Add the salsa to the mix and give it one more stir. Stuff pasta shells with the mix and set aside.
Pour the strained tomatoes into the baking dish. Place the shells on top and sprinkle them with marble cheddar cheese.
Cook on the oven’s middle rack for 12 minutes.
In a bowl, combine the Dairyland sour cream with the lime juice and fresh cilantro. Serve the shells topped with this mixture.
