Mexican Stuffed Shells can be prepared and ready to eat in about 1 hour or less. First you will boil your jumbo pasta shells according to the package directions for al dente noodles, it should be around 10 minutes. Drain the water out when they’re done cooking. While the noodles are cooking, saute your diced onions and ground beef until cooked through. Drain out any excess grease. Then add in some taco seasoning and then half a block of cream cheese. Combine salsa and enchilada sauce and pour half of it into the bottom of a 9x13inch baking pan. Fill the pasta shells with 1 to 2 tablespoons of the prepared ground beef mixture and place them into the baking pan. Pour remaining sauce over the top and cover the pan in foil and bake for about 30 minutes until the noodles are hot throughout. Remove the foil and top with the shredded cheeses. Bake for another 10-15 minutes until the cheese on top is all melted.