1. Arrange tortilla chips on a 12-in. pizza pan coated with cooking spray.
2. In a large skillet, cook and stir onion and garlic in oil until tender. Add chicken and taco seasoning. Stir in salsa; heat through. Spoon over chips; sprinkle with cheese.
3. Bake at 350° for 10-14 minutes or until cheese is melted. Top with tomato and green onions; serve immediately. Yield: 8 servings.