Step 1

Preheat the oven to 325 degrees F.

Step 2

Rub the turkey all over with the butter, including the cavity of the breast. Season generously with salt and pepper. Scatter the vegetables on the bottom of a roasting pan just large enough to hold the turkey. Set the turkey breast-side up in the pan. Roast until an instant-read thermometer inserted into the thickest part of the roast registers 160 degrees F, 2 to 2 1/2 hours.

Step 3

Transfer the turkey to a cutting board and tent loosely with foil for 30 minutes. (The breast temperature will continue to rise to 170 degrees F as it rests.)

Step 4

Pour any pan drippings into a fat separator or small bowl. Reserve 3 tablespoons of the fat; discard the rest or the fat. Add the pan juices to the broth. Add the reserved fat to the roasting pan and place on a burner over medium-high heat. Scrape up any browned bits from the bottom of the pan with a wooden spoon. Stir in the flour and cook for 2 minutes, stirring constantly. Whisk in the broth and continue to stir. Bring to a boil and cook until thickened, about 3 minutes. Strain the gravy, discarding the vegetables, and season with salt and pepper to taste.

Step 5

Carve the breast and serve with the gravy.