Remove the turkey from the refrigerator and let stand at room temperature for 30 minutes. With paper towels, pat the turkey very dry.
When ready to cook, preheat the air fryer to 350 degrees F for at least 5 minutes. In a small bowl, whisk together the oil, garlic, salt, rosemary, sage, thyme, black pepper, and mustard until evenly blended.
Rub all over the turkey.
Place the turkey in the air fryer basket, skin-side down (see notes if using a turkey with the ribs still attached). Cook for 20 minutes, then slide out the basket and carefully flip the turkey over.
Continue cooking for 30 to 50 minutes more, until an instant read thermometer inserted at the thickest part of the meat without touching bone registers 155 degrees F (poultry is considered cooked per the FDA at 165 degrees F, but its temperature will rise as it rests. DO NOT OVERCOOK or it will be dry). Boneless turkey breast in the netting will take longer than bone-in turkey breast without netting. Remove the turkey to a cutting board and cover with foil. Let rest at least 15 minutes.
To carve, cut each side of the breast away from the bone by running a large, sharp knife along and down each side of the breast bone using long, even strokes. Continue down the breast, following along the whole bone.
Lift the meat away in one large piece, then place it flat on the cutting board and cut crosswise into slices.
Repeat on the other side of the breast. Pull the remaining meat away from the bone and slice. Serve hot or at room temperature.
*If using bone-in turkey breast, be sure your air fryer is at least 5 quarts (my 5.5-quart air fryer can fit a turkey that is up to 5-pounds).
*I prefer to use a breast with the ribs removed, because it more easily fits in the air fryer AND I find it turns out more moist, because it can lay flat with the breast bone touching the bottom of the air fryer and cook more quickly and evenly. That said, if you can only find a turkey breast with the ribs still attached and don't want to remove them yourself, you can still make this recipe. To cook, lay the breast on its side (this is likely the only way it will fit in your basket) and cook for 25 minutes. Flip over to the other side and continue cooking until the breast reaches 155 degrees F at the thickest part. I also recommend brining a breast with the ribs attached to help keep it moist during cooking (see Dry Brine and Wet Brine for recipes).
**If using a boneless breast, such as a 3-pound Butterball breast, remove the outermost plastic netting and wrapper from the roast. Leave the inner string netting on (this holds the roast together as it cooks). It will take longer to cook than a bone-in breast because of how snugly it is held together.
TO STORE: Refrigerate turkey breast in an airtight storage container for up to 3 days.
TO REHEAT: Wrap turkey in an aluminum foil pouch and rewarm gently in a baking dish in the oven at 350 degrees F, drizzling some broth over the top before sealing the foil pouch and placing it in the oven.
TO FREEZE: Freeze leftovers in an airtight, freezer-safe storage container for up to 3 months. Let thaw overnight in the refrigerator before reheating.