Cut chicken, onion and pepper up into bite-sized pieces, about 1 inch by 1 inch. Set aside
Add all ingredients, except sugar, for the sauce in a small bowl, stir together
Turn Instapot to the saute setting. Add oil and heat up. Add garlic and saute for 1 minute
Add diced chicken and saute for about 30 seconds per side
Turn the instapot off
Add cut up onion and pepper on top of the chicke, top with the sauce
Cover the pot and secure the lid. Make sure the valve is set to sealing. Set the pressure cook button to 4 minutes and start it
Once completely cooked, vent and de-pressurize the instapot then open the lid
Remove the chicken and veggies with a slotted spoon and place in a large bowl
Set the instapot to the saute setting and stir in the sugar, 1 tablespoon at a time
In a small bowl, stir the slurry ingredients together
Add the slurry to the sauce (in the instapot) and stir together
Bring to a slight simmer and stir constantly, until thickened, about 2-3 minutes. Be sure to scrape the bottom so it does not burn
Once thickened, pour sauce over the chicken and veggies