Combine water or broth, soy sauce, honey, garlic and pepper in Instant Pot. Stir.
Add the chicken breasts to the Instant Pot.
Seal the lid and turn the steam valve to the sealing position.
Set Instant Pot to pressure cook/manual, high pressure. Set the cooking time according to the size of your chicken breasts. For fresh: 8 minutes for small (7-8 ounce) chicken breasts, 10 minutes for medium (10 ounce) chicken breasts, or 11 minutes for large (12 ounce) chicken breasts.
For frozen chicken breasts, add 3 minutes to the cooking times listed in step 4, and pressure cook (manual) at high pressure. Be sure that your chicken breasts are not stuck together as that will increase the pressure cook time.
The Instant Pot will take about 10 minutes to come to pressure and then will start counting down the cooking time. When it beeps to let you know the cooking time has finished, carefully quick release the pressure by using the handle of a long spoon to turn the steam valve to venting. (If your chicken breasts were frozen, do a 10-minute natural release instead of a quick release. Just leave the Instant Pot alone for 10 minutes before turning the steam valve to the venting position.)
Wait for the steam to escape and the pin to drop down. Then, carefully remove the lid.
Use an instant-read thermometer to test the internal temperature of the chicken. It should be at least 165 degrees F. If the temperature is lower, finish cooking the chicken using the Instant Pot's saute mode.
Remove chicken to a clean plate or cutting board.
In a small bowl, stir together the 2 teaspoons cornstarch and 1 tablespoon water. Turn the Instant Pot on saute mode and stir in the cornstarch mixture. Cook, stirring, until the liquid has thickened, 2-3 minutes. Turn off Instant Pot and remove the inner pot to stop the cooking process.
Slice the chicken and stir it back into the sauce in the pot. Serve with rice and vegetables, or as desired.
To Cook in a Slow Cooker:
Stir together water or broth, soy sauce, honey, garlic and pepper in slow cooker insert. Add the chicken.
Cover and cook on low for 3-4 hours or high for 2 hours, until chicken reaches an internal temperature of at least 165 degrees F.
Remove chicken to a clean plate or cutting board. Turn slow cooker to high setting.
In a small bowl, stir together 2 teaspoons cornstarch and 1 tablespoon water. Stir this into the liquid in the slow cooker and cook on high until thickened, about 20 minutes.
Slice or shred the chicken and stir it into the sauce in the slow cooker. Serve with rice and vegetables, or as desired.
To Make as a Freezer Meal:
Add water or broth, soy sauce, honey, garlic, pepper and chicken to a heavy-duty freezer bag.
Freeze flat for up to 3 months.
When ready to cook, thaw in cool water just until sauce is thawed. Transfer to Instant Pot and cook as directed above.