PREHEAT oven to 350°F. Spray 1-1/2-qt. casserole dish with cooking spray; set aside. Melt butter in large saucepan on low heat. Add flour, salt and red pepper; mix well. Cook and stir 2 min. or until bubbly. Gradually add milk, stirring until well blended. Increase heat to medium. Bring to boil, stirring constantly. Reduce heat to medium-low; simmer 3 to 5 min. or until thickened, stirring constantly. Gradually add 2-1/2 cups of the cheese; cook and stir 3 to 5 min. or until cheese is melted. Add broccoli, macaroni and onions; mix lightly.
SPOON into 1-1/2-qt. casserole dish; sprinkle with remaining 1/2 cup cheese.
BAKE 20 min. or until heated through.
KRAFT KITCHENS TIPS
Save 70 calories, 9 grams of fat and 5 grams of saturated fat per serving by preparing with fat-free milk and CRACKER BARREL 2% Milk Shredded Reduced Fat Extra Sharp Cheddar Cheese.
Prepare as directed, using thawed and drained frozen broccoli florets.
RECIPE COURTESY OF KRAFT FOODS