Preparation Whisk vinegar and mustard in small bowl to blend. Gradually whisk in oil. Whisk in shallots. Season vinaigrette to taste with salt and pepper. Trim dark green tops from leeks; then trim root ends, leaving base intact. Cut leeks lengthwise into quarters. Rinse under cold water to remove any soil. Working in batches, steam leeks on rack in large pot until tender, about 8 minutes. (Vinaigrette and leeks can be prepared 1 day ahead. Cover separately and refrigerate. Bring to room temperature and rewhisk vinaigrette before using.) Arrange leeks on large platter. Drizzle vinaigrette over. Sprinkle alternating bands of chopped egg yolks, egg whites, and parsley over and serve.
Preparation Whisk vinegar and mustard in small bowl to blend. Gradually whisk in oil. Whisk in shallots. Season vinaigrette to taste with salt and pepper. Trim dark green tops from leeks; then trim root ends, leaving base intact. Cut leeks lengthwise into quarters. Rinse under cold water to remove any soil. Working in batches, steam leeks on rack in large pot until tender, about 8 minutes. (Vinaigrette and leeks can be prepared 1 day ahead. Cover separately and refrigerate. Bring to room temperature and rewhisk vinaigrette before using.) Arrange leeks on large platter. Drizzle vinaigrette over. Sprinkle alternating bands of chopped egg yolks, egg whites, and parsley over and serve.