1Heat oven to 350°F. Spray 8-inch square (2-quart) glass baking dish with cooking spray. In 1-quart saucepan, heat 1 inch water to boiling. Add asparagus; cook uncovered 2 minutes. Drain thoroughly.
2In baking dish, mix asparagus, bell pepper and onions. In medium bowl, stir 1 1/2 cups of the cheese and the remaining ingredients until blended; pour into baking dish.
3Bake uncovered 35 to 40 minutes, sprinkling with remaining 1/2 cup cheese for last 5 minutes of baking, until knife inserted between center and edge comes out clean.