To the instant pot, add the chicken, BBQ sauce, onion, bell pepper, and garlic.
Put the lid on and set the valve to sealing. Set to cook on manual high pressure for 12 minutes.
Allow it to natural pressure release for 10 minutes, then release the remaining steam if needed and remove the lid.
Stir in the pineapple chunks and set to keep warm until the mixture is heated through.
Steam the cauliflower rice in a saucepan on the stovetop or in the microwave for a couple of minutes at a time until warmed through and softened.
Scoop the Hawaiian BBQ Chicken mixture over the steamed cauliflower rice, and top with chopped bacon & sliced green onion.