1. In large nonstick skillet cook onion in oil over medium-high heat about 3 minutes or until tender. Stir in MORNINGSTAR FARMS Meal Starters Grillers Recipe Crumbles, water and taco seasoning. Cook over medium heat until most of the liquid evaporates, stirring frequently. Remove from heat. Stir in tomato.
2. Spoon filling into taco shells. Top with cheese and lettuce. Serve immediately.