Preheat oven to 425 degrees. Melt 2 tablespoons Country Crock® Spread in large nonstick skillet and saute broccoli and red bell pepper until crisp tender. Whisk milk and flour in large bowl. Add chicken, cooked vegetables, 2 cups cheese, and onion powder; toss to mix. Pour into 8-inch baking dish.
Combine remaining 1 tablespoon Spread and remaining 1/4 cup cheese in small cup. Sprinkle over top of casserole.
Bake 30 to 35 minutes or until mixture is bubbly around edges.