In a large skillet, cook ground beef until no longer pink. Drain fat. Add onion, water, soy sauce, parsley, basil and garlic powder. Simmer 10 minutes, until liquid is evaporated.
Split the hoagie rolls. Slather them with sauce, and put cheese on top. Place them under the broiler until cheese melts, 1-2 minutes. Divide ground beef between the buns and serve.
Can make sauce in advance and refrigerate until ready to serve. The sauce will keep for up to a week in the refrigerator.