Radish greens, washed and trimmed
Chopped onion
Potatoes, diced and cooked
Chicken or vegetable stock, optional
Heavy cream, optional
Salt and pepper

Cook potatoes in water or stock.  Save potato water or stock.  Melt butter in large saucepan and add onions.  Cook until golden.  Stir in radish tops over low heat until wilted.  Combine potatoes with radish tops and puree in food processor or blender.  Add stock and optional cream to achieve desired soup consistency.  Add salt and pepper to taste.