Mix together all of your spices in a small bowl. Set aside.
Remove your turkey breast from the packaging, and remove any and all gravy packets or items that came with the turkey.
Rub your spice mixture all over the turkey breast, so that it is completely covered. Set aside.
Turn your Instant Pot on to SAUTE.
Add the butter to the Instant Pot.
Place your turkey in the Instant Pot breast side down and sear for about 8 minutes.
Remove the turkey from the Instant Pot and set aside.
Pour 1 cup of chicken stock in the bottom of the Instant Pot and scrape the bits from the bottom of the pot to loosen them.
Place the trivet inside the Instant Pot and place the turkey, breast side up in the Instant Pot.
Secure the lid.
Turn the valve to SEALING.
Cook on HIGH PRESSURE for 28 minutes.
Press CANCEL.
NATURALLY RELEASE the pressure, do not quick-release.
Once pressure is released, remove the lid, turkey, and trivet.
Press SAUTE.
In a separate small bowl, make your cornstarch slurry using cornstarch and 4 tbsp water.
Add them to the Instant Pot and whisk until the gravy has thickened, about 3-5 minutes.
Notes
I find the easiest way to handle the bone-in turkey breast in your Instant Pot is to use two sets of metal tongs with serrated edges.
My 6qt Instant Pot was large enough to handle a 5lb turkey breast. If you will be using a larger turkey breast, I recommend using a larger Instant Pot.