Preheat oven to 375°F. Heat 1 tablespoon of the oil in large nonstick skillet on medium-high heat. Add chicken, onion and 2 tablespoons of the Seasoning; cook and stir 6 minutes or until chicken is no longer pink. Stir in tomato sauce, orange juice and vinegar. Cook on medium heat 5 to 10 minutes or until sauce is thickened. Remove from heat; cool slightly.
Place 4 tortillas on baking sheet. Top with chicken mixture, cheese, then remaining tortillas. Brush with remaining 1 tablespoon oil. Sprinkle with remaining 1 teaspoon Seasoning.
Bake 10 minutes or until cheese is melted. Cut into wedges.