You can swap any fall veggie -- brussels sprouts, turnips, or cabbage -- into this warm salad. Don't skip the celery leaves: they may seem delicate, but they pack a lot of flavor.
Heat oven to 425 degrees. On two baking sheets,arrange carrots, onion, and squash; drizzlewith 2 tablespoons oil, and season with salt andpepper. Roast, turning once, until caramelizedand tender, about 30 minutes.
Meanwhile,place lentils and shallot in a medium saucepanand cover with water by two inches.Bring to a boil, then simmer, covered, untillentils are tender, about 20 minutes. Drain;discard shallot. Season with salt and pepper.
Combine vinegar and mustard. Pour remaining3 tablespoons oil in a slow steady stream,whisking constantly. Toss lentils and celerywith vinaigrette and season with saltand pepper. Spoon over roasted vegetables.Garnish with celery leaves.
Make sure you cut all the vegetables to about the same size for even roasting.