HEAT oven to 375ºF.
COMBINE vegetables, garlic, black pepper and oil; spread onto bottom of shallow foil-lined pan.
BAKE 25 min. or until vegetables are lightly browned.
TRANSFER vegetables to large saucepan. Add broth; stir. Bring to boil; simmer on medium-low heat 20 min., stirring occasionally. Remove from heat; stir in mustard. Add to blender, in batches; blend until smooth.