Arrange sliced onion, oranges, lemon, and garlic on bottom of crockpot. Sprinkle salt, pepper (and dried poultry seasoning, if you are using) to each side of the chicken tenderloins. Place over the top of the onion, orange and lemon layer. If using fresh herb packet, scatter herbs over the top of the chicken. Add 1/2 c. water (optional). Cook on low heat for 4-6 hours. Take the herbs out, take the chicken out, strain the juices. Use the sauce to pour over chicken, this can be reduced down to concentrate the flavors more or when not on HCG I thicken the sauce with a little cornstarch and water to make a yummy thick sauce.