1 med. head cauliflower
2 tbsp. water
1/2 c. mayonnaise
1 tsp. finely chopped onion
1 tsp. prepared mustard

Put cauliflower and water in large microwave casserole dish. Cover and microwave 8-9 minutes on high. Turn over half way through. Mix rest of ingredients and spoon over head. Sprinkle with 1/2 cup shredded Cheddar and microwave uncovered 1 1/2 to 2 minutes on reheat.