Roasted leeks become tender and sweet with deeply caramelized edges, then are dressed with a tangy mustard vinaigrette and crunchy toasted hazelnuts. Serve warm or at room temperature as a simple fall side alongside roasted chicken, pork, or hearty grains.
1. Preheat the oven to 425 F. Trim the dark green tops and root ends from the leeks, then cut eat each leek in half lengthwise. Rinse thoroughly between layers and pat dry.
2. Arrange leeks cut side down on a sheet pan. Drizzle with olive oil and season with salt and black pepper. Roast until tender and caramelized around the edges.
3. While the leeks are roasting, make the vinaigrette. Whisk together the dijon, cider vinegar, honey, salt and pepper. Slowly whisk in the olive oil until combined.
4. Arrange the warm roasted leeks on a serving platter and spoon the mustard vinaigrette over the top. Let sit for a few minutes so the leeks absorb some of the dressing.
5. Scatter with toasted hazelnuts and parsley and finish with freshly cracked black pepper.