Place potatoes and carrots, whole, in a vegetable steamer, covered, over boiling water for fifteen minutes. Cut carrots into 1/2 inch / 13 mm slices. Peel potatoes and cut into 1 inch / 2.5 cm cubes. Set aside.
Melt margarine in a large heavy saucepan. Add potatoes, carrots, onion, celery, broccoli, salt, bouillon, cover and simmer for 10 minutes, stirring occasionally.