Wash and trim all vegetables. Chop into bite-sized pieces. Place in a roasting pan and toss with rendered fat or drippings. (olive oil may be substituted for fat, although it will not yield the same savory effect.) Roast in the oven at 400 degrees until tender, about 40 minutes to 1 hour, stirring occasionally to coat with fat and ensure even browning. salt and pepper to taste.