Heat oven to 375 degrees. Remove organ meats from chicken. Rinse chicken well with cold water and pat dry. Cut off tops of garlic exposing the individual cloves, but don't remove the garlic skins. Place whole cloves of garlic and 1/4 cup whole fresh thyme or rosemary inside chicken cavity. Tie drumsticks together with string and place chicken breast side up in a roasting dish. Roast uncovered for 45 minutes. Cut carrots and celery into 1-inch pieces. Slice unpeeled potatoes into 1 1/2-inch pieces. Peel the onions and cut into wedges. After 45 minutes, remove chicken from oven. Arrange the vegetables around the outside of the chicken. Melt the margarine and stir in the thyme or rosemary. Drizzle margarine over the chicken and vegetables. Cover and bake another 45-60 minutes or until chicken is no longer pink or a meat thermometer reads 180 degrees.