If turkey breast is frozen, thaw overnight in the fridge and then set out on the counter for 30 minutes before cooking. If there is a turkey neck or gravy packet in the cavity, remove and discard.
Place the turkey breast in a baking dish or on a platter and run with butter, garlic, and chopped herbs. (If the breast is skin-on, be sure to rub some butter under the skin AND on top.)
Place the turkey breast into the air fryer basket, top side up. Cook at 375 degrees F for 60 minutes, rotating halfway through the cooking time. When the cooking time is up, check that the internal temperature is 160 degrees F with a meat thermometer.
When there are about 10 minutes left on the air fryer, start the glaze. Add the mustard vinegar, brown sugar, orange juice, and orange zest to a medium saucepan. Whisk together.
Place the saucepan over medium heat and bring to a simmer. Cook for 5 minutes. Remove from the heat and whisk in the butter.
Brush the glaze all over the turkey breast and air fryer for another 3 minutes at 375 degrees F to caramelize the glaze. Remove to a cutting board and rest for 10 minutes before serving.
Notes
Be sure to choose a turkey breast that will fit into your air fryer. I usually get a 4-pound bone-in breast to feed our family of four. You can also use boneless turkey breast if you prefer. Use the chart below to help determine cooking temperature and time for different size turkey breasts...
2 pounds for 40 minutes at 350 degrees F
3 pounds for 45 mins to 1 hour at 360 degrees F
4 to 5 lbs for 50 to 60 mins at 360 degrees F
Each air fryer is different and cooking times may vary. Start checking for doneness 10 minutes before the cooking time is up.