In the Instant Pot, place the butter, sugar, chili powder, Worcestershire sauce, dry mustard, garlic salt, Paprika, water, and brown sugar.

Turn the Instant Pot to 'SAUTE', and melt all ingredients together.

Bring the mixture to a boil, and boil for 1 minute. Turn off the Saute setting.

Cut the chicken breasts into thirds, and place in the Instant Pot, turning the pieces of chicken in the spice mixture to coat the chicken. (you may need to turn the chicken three or four times to completely coat it) When the chicken is coated, place the lid on the Instant Pot, and make sure the PRESSURE VALVE is set to SEALING.

Press the MANUAL button, and set the time to 16 minutes.

Let the Instant Pot build and release the pressure naturally (this is not a quick release).

When the Instant Pot has finished cooking, and goes to OFF, leave the lid on the Instant Pot for 10 minutes.

After the 10 minutes, turn the pressure valve to VENTING, and make sure all the pressure has been released, and float valve is down.

Remove the lid to the Instant Pot, and stir the chicken and sauce.

Turn the SAUTE setting on, and cook for 2 to 3 minutes, to thicken the sauce a little.

Turn the Saute setting off, stir the sauce, and spoon over the chicken, and allow the chicken to cool for a few minutes.

Serve with mashed Potatoes, and sauce ladled over chicken. Enjoy!