PREHEAT oven to 375°F. Place vegetables in large saucepan. Add enough cold water to cover vegetables. Bring to boil on medium-high heat; cook 8 to 10 min. or until vegetables are tender. Meanwhile, melt butter in medium saucepan on medium heat. Add flour, salt, black pepper and cayenne pepper; mix well. Cook and stir 1 min. Gradually add milk, stirring until well blended. Bring to boil on medium heat; cook 5 min. or until thickened, stirring constantly. Stir in cheese. Reduce heat to low; cook 1 min. or until cheese is melted, stirring constantly.
DRAIN vegetable mixture; spoon half into lightly greased 13x9-inch baking dish. Cover with half of the cheese sauce. Repeat layers. Cover with foil.
BAKE 45 min. or until heated through, removing the foil after 30 min.
