Heat 2 Tbsp. dressing in large nonstick skillet on medium heat. Add peppers, onions and garlic; cook and stir 3 min. Add shrimp and remaining dressing; cook 3 min. or until shrimp turn pink, stirring frequently. Stir in chili powder; cook and stir 1 min. Remove from heat. Add half the cheese to shrimp mixture; mix well.