Add the chicken broth (or vegetable broth) to the bottom of the pot. Put a trivet into the pot overtop of the broth.
Remove the (thawed) turkey from its wrapper and pat dry. Remove any items from the inside of the cavity and rinse the turkey thoroughly. Pat dry with paper towels.
To a small mixing bowl, combine: melted butter, garlic powder, onion powder, rosemary, sage, thyme, lemon juice, salt and pepper. Mix to thoroughly blend. Brush this mixture over the entire turkey breast, rubbing it in with your hands.
Stuff the turkey breast with the celery, onion, garlic cloves, and fresh sprigs of thyme.
Place the turkey breast into the pot, onto the trivet, with the neck facing upward (the stuffed end).
Place the lid on the pot and close. Set the valve to the sealed position.
Set the Instant Pot to High Pressure for 6 minutes per pound. So for a 6.5 pound turkey breast, set it to 39 minutes. It will take 15-20 minutes to come to pressure before it starts to cook, so now is the time to prep another dish, if you have one.
When the timer goes off, do a natural release for 10 minutes, followed by a quick release to remove any remaining pressure.
Carefully remove the turkey from the pot to a serving dish (or roasting pan if placing under the broiler), and cover with foil to keep warm.
Cancel the Instant Pot action and turn it to 'Sauté'. In a small mixing bowl, combine the cornstarch with the water. Whisk to thoroughly combine.
Using a skimmer (listed in the 'Tools Used' section above), skim any excess fat from the broth. Slowly pour the cornstarch mixture into the pot of broth and whisk until the broth starts to thicken.
IF BROILING TURKEY: Place the turkey into an oven safe baking dish or pan. Brush the melted butter over the skin of the turkey and place under the broiler set on LOW for 3-4 minutes, or until the skin starts to brown. Keep an eye on the turkey!
Remove and serve with gravy and sides of choice. Check my post for some recommendations!