Cheesy Smashed Potatoes

1 lb. red potatoes (about 3 small), cut into chunks
1 cup bite-size cauliflower florets
1/4 cup BREAKSTONE'S Reduced Fat or KNUDSEN Light Sour Cream
1 cup KRAFT 2% Milk Shredded Reduced Fat Sharp Cheddar Cheese

PLACE potatoes and cauliflower in large saucepan. Add enough water to cover.

BRING to boil on high heat. Reduce heat to medium; simmer 20 min. or until vegetables are tender. Drain; return to pan.

ADD sour cream; mash until vegetable mixture is light and fluffy. Stir in cheese.