BROWN meat with onions in large saucepan; drain.
STIR in flour; cook and stir 2 min. Add broth and tomatoes; cook on medium-low heat 5 min. or until heated through. Stir in VELVEETA; cook and stir 8 to 10 min. or until VELVEETA is completely melted and soup is heated through.
SPOON into soup bowls; top with relish. Serve with crackers.