PREPARE: Preheat the oven to 325˚ Fahrenheit and adjust the oven rack to about 10 inches from the bottom to allow room for a deep pan.
ADD VEGGIES: Arrange the onion and celery in the bottom of a 5.6-quart Dutch oven or large covered pan. Pour the broth over the vegetables and then add the turkey breast roast (held together with twine or elastic binding) on the top of the vegetables.
MAKE THE HERB BUTTER: In a small pot, melt the butter over medium heat. Reduce the heat to medium-low and whisk in the honey, lemon juice, and mustard. When the mixture is smooth, add the garlic, rosemary, sage, and parsley. Allow to very slowly simmer for about 2 minutes.
SEASON THE TURKEY: Generously coat the herb butter on all sides of the turkey and pour any remaining butter over the vegetables in the bottom of the pan. Sprinkle with ½ teaspoon of salt and ¼ teaspoon of pepper on all sides.
COOK: Cover and bake in the prepared oven for 50 minutes or until it reads 145 in the center with a quick read thermometer.
REST AND SERVE: Remove the turkey from the oven and remove the lid. Let the turkey rest for 20 minutes. Remove the twine, discard the vegetables, and slice the turkey into 1” pieces. The center should be no longer pink and the juices should run clear.
FOR THE GRAVY
Remove the turkey breast to a cutting board and strain the juices remaining in the pot using a sieve over a bowl. Discard the vegetables and pour the juices back into the pot or dutch oven.
Heat the pot over medium heat and allow it to come to a simmer for 5 minutes to reduce just a little (to about ¾ the original amount). In a small bowl or ramekin, mix the cornstarch with about 2 tablespoons of water and stir to dissolve it. Pour the cornstarch slurry into the reduced dripping and whisk until it thickens.
Remove the pan from the heat, taste and season with additional salt or pepper if it's needed.
If your turkey breast is not tied off when you get it, read the post to find a useful video on how to do it.
Look for a poultry herb pack in the produce department to save money, use about 1 tablespoon of each herb
To use dried herbs, reduce the amount to 1 teaspoon each
Do not skip letting the turkey rest or it may not be completely cooked!
If your turkey is larger than 3 pounds, it will add additional cooking time to get to the desired temperature.