Heat broth in large saucepan to boiling. Add broccoli, onion and garlic. Bring to boil; reduce heat to low. Cook, covered, for 5 to 7 minutes or until broccoli is tender. Remove from heat; cool slightly.
Transfer half of vegetable-broth mixture to blender or food processor (in batches, if necessary); cover. Blend until desired consistency. Return to remaining mixture in saucepan.
Combine dry milk, water and flour in medium bowl; mix well. Stir into soup; add salt and pepper. Heat to serving temperature.