Remove any giblets or chicken neck from chicken’s cavities. Liver should be discarded; reserve the rest for Chicken Stock. Pat chicken dry inside and out with paper towels. Carefully loosen the skin over the breast by working your fingers between skin and flesh by loosening any connective tissue; set aside and allow to come to room temperature while oven preheats.

Position rack in middle of oven. Preheat oven to 450°F/230 ° Have a roasting pan ready that is large enough to hold the chicken with space all around.

Combine softened butter, oil, rosemary, salt, pepper and citrus zest in a small bowl. Use this mixture to rub all over the bird’s skin and also under the skin, slathering the breast meat.

Prick the orange or tangerine several times with a fork and stuff into cavity of chicken. Place chicken, breast side up, in roasting pan. Place in oven, close door and lower temperature to 425°F/220°

Roast chicken for about 50 minutes undisturbed. Do not open oven door. The chicken is done when it registers 165°F/74°C in the thickest part of the thigh (make sure thermometer is not touching bone). You can also jiggle the wings and legs and they should feel loose in their sockets, or prick in one spot with the tip of a knife and juices should run clear. Depending on exact size of chicken and how cold it was when it went in the oven the cooking time might vary by about 10 minutes.

Rest the chicken for about 10 or 15 minutes, which will allow the juices to distribute. Chicken is ready to serve. Leftovers will keep for about 4 days refrigerated in an airtight container or wrapped well with plastic wrap.