In a small bowl, combine minced garlic, chopped rosemary, thyme, olive oil, salt, black pepper, lemon zest, and lemon juice to create a fragrant herb paste.
Pat the turkey breast dry with paper towels. Carefully loosen the skin from the breast without fully removing it, creating pockets.
Squeeze about half of the herb paste under the skin and rub the remaining paste all over the outside of the turkey breast.
Place the quartered onion in the bottom of a roasting pan, then set the turkey breast on top of the onions. Pour the chicken broth into the pan.
Roast the turkey breast in the preheated oven for about 1.5 to 2 hours, or until the internal temperature reaches 165°F (74°C). Baste the turkey with pan juices every 30 minutes.
Once cooked, remove the turkey from the oven and let it rest for 15-20 minutes before slicing. This helps lock in the juices.
Serve the turkey sliced with the pan juices drizzled on top for added flavor and moisture.
Notes
Let the turkey rest before slicing to retain juices.