Preheat oven to 375 degrees and spray a baking pan with nonstick cooking spray.

Simmer lentils in 2 cups of water and ½ teaspoon of salt if desired, for 20-30 minutes or until tender. Drain any remaining water and let lentils cool a bit.

Peel carrots and parsnip and cut into ½ inch wide coins. Toss with up to 1 tablespoon of olive oil and sprinkle with salt and pepper. Spread vegetables in one layer on the baking sheet. Reserve any remaining oil in the bowl for the leeks. Roast vegetables for about 15-20 minutes or until tender, flipping them halfway through so they caramelize evenly.

Trim leak, cutting off bulb and dark green stems, and any tough outer layer of the light green stems. If desired, reserve bulb and dark stems for stock.

Slice light green part into thin round strips, and rinse well to remove any dirt or sand. Place leeks in the bowl and toss with the oil, salt and pepper that remains from the vegetables.

When the vegetables are tender, remove from the oven and toss with the lentils in a large mixing bowl.

Spread the leeks on the baking pan, and roast for 10-12 minutes until they caramelize and start to turn dark and crispy.

Meanwhile, prepare the vinaigrette: Mix lemon juice, honey and 2 tablespoons olive oil together. Remove thyme leaves from their stem and add to vinaigrette. Season with salt and pepper.

Pour dressing over vegetables and lentils, toss to combine.

Serve lentil-vegetables over a bed of arugula, and sprinkle with crisped leeks.