Make a slit on the top of the leeks and wash well in between the leaves. Attach them in a bundle with kitchen twine and wrap butcher style (wrap around twice and knotted).
Bring a pot of water to a boil; add salt and plunge leeks in water for about 5-10 minutes until cooked but still firm. Remove leeks from boiling water and plunge them in an ice bath for a few minutes to stop the cooking and retain its color. Drain.
In a small bowl, mix together mustard and vinegar. Add oil slowly to make a sauce.
Lay leeks on plate; sprinkle eggs on top and pour vinaigrette over. Garnish with parsley and chives. Serve warm or cold as an appetizer. Serves 4.
Approximate Nutrient Analysis per serving (not including salt to taste):
330 calories, 23 g fat, 3.5 g saturated fat, 95 mg cholesterol, 105 mg sodium, 25 g carbohydrate, 3 g fiber, 7 g sugar, 6 g protein