COOK onions in hot oil in large saucepan on medium heat 5 to 7 min. or until tender. Stir in milk. Bring to simmer, stirring frequently.
ADD VELVEETA and broccoli; cook and stir 6 to 8 min. or until VELVEETA is melted and broccoli is heated through.
STIR in ham and corn; cook 4 to 5 min. or until heated through, stirring occasionally.