Heat 2 teaspoons oil a large soup pot over medium heat. Stir in the leek and saute until tender. Mix in the potatoes and stir for a minute. Pour in water or broth. Bring the mixture to a boil. Reduce heat, and simmer 15 minutes or until potatoes are soft.

In a separate pan, heat last teaspoon of oil and saute garlic 1 minute.  Add radish greens and saute until wilted.  Put greens in soup pot.  Add salt to taste.

Using immersion blender, puree soup. Adjust salt and pepper to taste.  Serve in bowls and top with chopped radish.