Leeks in Mustard Sauce

Directions

1. Cut leeks into 1-1/2-in. slices, then julienne. In a large cast-iron or other heavy skillet, saute leeks, onions and garlic in oil until tender.
2. Meanwhile, in a small heavy saucepan, whisk the egg yolks, water and lemon juice. Cook and stir over low heat until mixture begins to thicken, bubbles around the edges and reaches 160°, about 20 minutes. Add butter, 1 tablespoon at a time, whisking after each addition until melted. Remove from the heat; stir in mustard and pepper.
3. Transfer leek mixture to a serving bowl; top with mustard sauce.