Prepare and bake potatoes. Heat oven to 475. Cut each potato length-wise into halves. Scoop out potatoes, leaving a 1/4 in shell. Brush outsides and insides of shells with butter. Place shells, cuit sides up, on ungreased cookie sheet. Bake uncovered until edges are brown. 15 - 20 min.
Cook and stir ground beef in 10-in skillet until brown; drain. Stir in tomatoes and seasoning mix; break up tomatoes. Heat to boiling; reduce heat. Simmer uncovered, stirring occasionally, 20 min. Spoon beef mixture into shells; sprinkle with cheese. Heat just until cheese is melted. Top each with dollop of sour cream and sprinkle with green onions.
Serve with buttered green peas and cole-slaw.