Preheat oven to 350°F. Heat 1 tablespoon of the oil in large skillet on medium-high heat. Add meat; cook and stir 3 minutes or until no longer pink. Remove from skillet. In same skillet, heat remaining 1 tablespoon oil. Add onion and bell pepper; cook and stir 3 to 5 minutes. Return meat to skillet. Stir in water and Seasoning Mix. Cook and stir 3 minutes or until heated through.
Divide filling among each of 4 flour tortillas on baking sheet. Sprinkle each with 1/2 cup cheese. Top each with second tortilla.
Bake 5 minutes or until cheese is melted. Cut into wedges. Serve with desired toppings.