• 6 large leeks
• butter
• salt
• freshly ground pepper
• white sauce (recipe follows)

Prepare the leeks: Cut away the root at the base and most of the green leaves, leaving the white of the leeks and a little of the pale green part. Cut the leeks in half lengthwise, rinse them well under running water, and steam them in a steaming basket until tender, about 15 minutes. When done, cut the leeks into pieces about 1½