Leek And Potato Puree Recipe

Trim roots and most, but not all, of the green leaves from leeks, leaving each leek about 7 inches long.
Split down to but not through the base and wash thoroughly.
Bring 3 quarts salted water to a boil in a pot, add leeks, and cook until tender, about 15 minutes.
Drain and chop.
Meanwhile, peel the potatoes.
Cover them with cold water in another pot.
Add salt and bring to a boil.
Reduce heat and cook until potatoes are very tender, 20 to 40 minutes, depending on the size.
Drain and reserve.
Melt 3 tablespoons of the butter in a skillet.
Add the garlic and cook over low heat until lightly colored, about 15 minutes.
Add leeks and an additional 3 tablespoons butter and continue to cook, stirring occasionally, for 15 minutes.
Transfer leeks and butter mixture to the bowl of a food processor fitted with a steel blade, and puree until smooth.
Mash the potatoes, adding heavy cream as needed.
Stir in the leek puree and remaining 6 tablespoons butter; season with salt and pepper.
Reheat gently until steaming.