Clean leeks by filling your sink with water and soaking the sliced leeks for a couple of minutes (leeks will float, but dirt and grit will sink to the bottom). Remove leeks with a slotted spoon, then drain dirty water. Blanche leeks in boiling water for a couple of minutes until slightly tender. Drain water from leeks then rinse leeks in very cold water for 1 minute. Allow leeks to drain well. In a separate bowl combine olive oil, vinegar, Dijon mustard and dry seasonings, and stir well. Toss leeks and vinaigrette together in a bowl. Serve chilled.
Recipe courtesy of The Butcher Shoppe.