01 - Preheat the oven to 375°F.
02 - In a small bowl, mix softened butter, olive oil, parsley, rosemary, thyme, garlic, lemon zest, salt, and pepper until well combined.
03 - Pat the turkey breast dry with paper towels. Carefully loosen the skin over the turkey breast and rub half of the herb butter mixture under the skin. Rub the remaining mixture over the top of the skin.
04 - Place the onion, celery, and carrots in the bottom of a roasting pan. Set the turkey breast on top of the vegetables, skin-side up.
05 - Pour the chicken broth into the pan, not over the turkey.
06 - Roast uncovered for 1 hour to 1 hour 15 minutes, or until a meat thermometer inserted into the thickest part of the breast reads 165°F.
07 - Baste the turkey breast with pan juices halfway through roasting.
08 - Remove from oven, tent loosely with foil, and let rest for 10–15 minutes before slicing.