Cook noodles as directed on package; drain and cut in half crosswise. In saucepan, cook garlic and thyme in butter. Blend in flour; cook, stirring constantly. Stir in milk; cook, stirring constantly until thickened. Season sauce with salt and pepper. In buttered, 2 litre microwaveable dish, layer one third of noodles, sauce, cheese, ham and asparagus. Repeat layers twice. In microwave, cover and cook on high 10 minutes, turning twice.