Combine water or broth, soy sauce, honey, garlic, and pepper in the Instant Pot. Whisk until the honey dissolves.

Add the chicken breasts to the Instant Pot.

Seal the lid and move the steam valve to the sealing position.

Set the Instant Pot to pressure cook/manual, high pressure. Set the cook time according to the size of your chicken breasts. For fresh (not frozen) chicken:

8 minutes for small (7-8 ounce) chicken breasts

10 minutes for medium (10 ounce) chicken breasts

11 minutes for large (12 ounce) chicken breasts

For frozen chicken breasts, add 3 minutes to the cooking times listed and pressure cook (manual) at high pressure. Be sure your chicken breasts are not stuck together, as this will increase the cook time.

The Instant Pot will take about 10 minutes to come to pressure before starting the cook time. When the cook time ends, carefully quick release the pressure by using the handle of a long spoon to move the steam valve to venting. (If your chicken was frozen, do a 10-minute natural release instead of a quick release. Leave the Instant Pot alone for 10 minutes before moving the steam valve to the venting position.) Wait for the steam to escape and the pin to drop, then carefully remove the lid.

Use an instant-read thermometer to test the internal temperature of the chicken. It should be at least 165°F. If it’s lower, finish cooking using the Instant Pot's sauté function.

Remove the 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 sauté mode and stir in the cornstarch mixture. Cook, stirring, until the liquid has thickened, 2-3 minutes. Turn off the Instant Pot and remove the inner pot to stop the cooking process.

Slice the chicken and serve with the honey garlic sauce, rice, vegetables, or as desired.