Make Shells & Cheese according to package instructions, set aside. Brown and drain ground beef. Add tomato sauce and chili powder to ground beef (use more or less chili powder to taste).
Pour beef mixture into 1 1/2 to 2 qt casserole dish. Make an indention (a lake) in the burger mixture and pour the prepared shells & cheese into it. (Do not mix the beef and pasta together, they will combine as you dip from the dish.)
Heat in microwave 2 minutes or until heated through. Serve.