MIX first 3 ingredients in medium saucepan. Add VELVEETA; cook on medium heat 5 min. or until VELVEETA is melted and mixture is well blended, stirring frequently.
ADD cheddar; cook and stir 2 to 3 min. or until melted. Transfer to fondue pot or small slow cooker set on low heat.
SERVE with sliced apples, broccoli florets and French bread cubes.