Leeks in Vinaigrette

• 3 pounds small leeks

See instructions for paring and cleaning leeks. Use only the white and very light-green parts of the leeks. Tie them into bundles as for asparagus, plunge them into salted, boiling water, and cook, covered, at a simmer for about ten minutes or until they are only just done, the flesh offering but the slightest resistance to the point of a small sharp knif