Trim cauliflower and separate into flowerets. In a saucepan combine cauliflower with peppers and onion; cover with water and salt. Bring to a boil; cover and cook for about 10 to 12 minutes, or until tender

In another saucepan; melt butter over medium-low heat. Stir in flour and stir until smooth and bubbly. Gradually add milk, stirring constantly. Continue cooking and stirring until thickened. Stir in 1/2 cup of the cheese. Pour sauce over cauliflower and transfer to a lightly buttered 1 1/2-quart baking dish. Top with buttered bread crumbs or French fried onions. Bake at 350° for about 30 minutes. Sprinkle with remaining cheese the last 5 minutes of baking time.
Serves 4.