Pull the turkey breast out of the refrigerator 45 minutes before you plan to roast it. This takes the chill off the meat and helps it cook more evenly. Heat your oven to 325 degrees Fahrenheit while the turkey sits on the counter.

In a small bowl, mix the softened butter with the rosemary, thyme, garlic, salt, and pepper until everything is combined. It should look like a thick, fragrant paste.

Scatter the chopped onion, celery, and carrots across the bottom of your roasting pan. Pour the broth over the vegetables. Set the turkey breast on top of the vegetables, skin side up. The veggies act as a natural roasting rack and soak up all the drippings as the turkey cooks.

Use your fingers to gently loosen the skin from the breast meat without tearing it. Slide about half the herb butter directly underneath the skin and spread it over the meat as evenly as you can. Rub the remaining butter all over the outside of the skin. This double layer is what gives you deep flavor and crispy skin.

Roast uncovered for about 1 hour and 45 minutes to 2 hours. If the skin looks deeply golden before the meat is done, tent loosely with foil and remove it for the last 10 minutes of cooking to crisp back up.

Start checking the internal temperature at the 1 hour 45 minute mark. Insert an instant-read thermometer into the thickest part of the breast without touching bone. You are looking for 165 degrees Fahrenheit. Pull it from the oven the moment it hits that mark.

Transfer the turkey breast to a cutting board and tent loosely with foil. Let it rest for at least 20 minutes before carving. This rest is not optional. It is what keeps the juices in the meat instead of running onto your board. Pour the pan drippings into a measuring cup or fat separator to use for gravy.

Carve by running a sharp knife along one side of the breastbone, then slicing the meat crosswise into thick pieces. Arrange on a platter and spoon a little of the warm pan drippings over the top before serving.