Heat all ingredients for the sauce in a small skillet over medium heat and bring to a full but gentle boil. Cook whisking continuously, until sauce is reduced by half its volume, about 3 to 5 minutes. Set aside until ready to use.

Turn the Instant Pot on the saute function and allow it to warm up. Add the coconut oil, followed by the chopped chicken, ginger, and garlic. Allow the chicken to brown for 1 to 2 minutes before adding the rice, water, and half of the teriyaki sauce. 

Secure the lid on the Instant Pot and put it on the Pressure Cook (high) setting for 3 minutes. Once finished on pressure cook, allow the steam to release on its own for 10 minutes, remove the lid of the Instant Pot, and add the vegetables. 

Put the Instant Pot back on the saute setting and stir everything together. Continue cooking and stirring until vegetables have reached desired done-ness. 

Stir in the rest of the sauce. Serve chicken teriyaki with chopped green onion, sesame seeds, and red pepper flakes.