Cook meat until done. Drain, ... Mix onions and lettuce together, arrange equal amounts on plates, spoon casserole over top. Garnish with sour ... 6 to 8 servings.
In a 1 1/2 quart casserole, crumble beef. Stir in ... tostada shells and lettuce. If desired, top with ... additional taco sauce, if desired. Serves 6.