1. In a large skillet over medium heat, brown the ground beef. Drain off excess fat.
2. Stir in Taco Seasoning with water. Mix well with browned beef.
3. Bring to a boil, reduce heat and simmer for 10 minutes, stirring occasionally.
4. Preheat oven to 375 degrees F (190 degrees C). Warm taco shells for 3-5 minutes.
5. Put vegetables and cheese on a plate.
6. Spoon the hot meat filling into the warm taco shells and spoon 1 tablespoon taco sauce over the meat.
7. Top each taco with tomato and lettuce.
8. Top lettuce with 2 tablespoons cheese.
9. Return the filled taco shells to the preheated oven to melt the cheese (optional) and serve.