Heat oven to 350 degrees. In a baking dish, coat chicken, potatoes, carrots, rhubarb, leeks and garlic with olive oil. Season all with salt and pepper, and add lemon thyme sprigs and savory leaves. Dot with butter, drizzle with honey, add wine and roast for 35-40 min until chicken reaches 165 degrees internal temp, basting with pan juices 2-3 times. Place all on serving platter and top with chervil and tarragon. For a finer sauce, add roasted rhubarb, pan juices, and half of roasted garlic, tarragon and chervil in blender, then puree, adding a bit of chicken stock and melted butter to thin. Pour over chicken.