Begin by thawing your turkey breast if it's frozen. Allow 24 hours for every 5 pounds of turkey to thaw in the refrigerator.
Preheat your oven to 325°F.
In a small bowl, mix together the softened butter, minced garlic, salt, pepper, thyme, rosemary, and sage to create your herb butter.
Prepare the turkey breast by removing any packaging and patting it dry with paper towels. Season the outside lightly with additional salt and pepper.
Gently loosen the skin of the turkey breast and spread a generous amount of the herb butter underneath, covering the meat evenly. Apply the remaining herb butter over the outside of the turkey breast.
Place the turkey breast in a roasting pan or on a baking sheet, and position it in the center of the oven.
Roast the turkey breast for 15–20 minutes per pound, or until the internal temperature reaches 165°F when measured at the thickest part of the breast.
Once cooked, remove the turkey breast from the oven and tent it with aluminum foil. Let it rest for at least 15 minutes before carving to allow the juices to redistribute.