Switch on the Instant Pot in saute mode. Add in the sesame oil, and let it get hot. Add the cashew nuts and saute until they turn slightly golden and aromatic. Remove from the pot and set aside for later use.
Into the add the sliced garlic. Saute for 1few secs and then add the diced onion. Saute for a min.
Now add the diced bell pepper along with the white onion. Saute for 2 mins. If you want the peppers to be crunchy, you may saute them, remove them from the pot, and add them later. Else let them be.
Now add the boneless chicken pieces. Saute for a min.
Next, add the Soy Sauce, Sweet chili sauce, Rice Vinegar, and Brown Sugar. Combine once.
Now add the black pepper powder and the required salt.
Also, add ½ cup of Water or chicken stock. Combine everything and deglaze the pot once. Close the Instant Pot. move the pressure value to the sealing position. Press cancel and then press the pressure cook option. Set 5 mins in high pressure.
Once the cooking time is over. Do a quick release and open the Instant Pot. Combine the corn flour with water and make it a slurry. Switch on the Instant Pot in saute mode and add the corn flour slurry.
The sauce thickens in a min or two and then switch off the Instant Pot. Now add in the fresh Basil leaves. you may add them as a whole or tear them roughly and then add them.
Also, add the roasted cashew nuts. Mix everything once and then keep the Instant Pot closed for another 10 mins.
Open after 10 mins. The basil leaves will have wilted. Garnish with spring onion greens and toasted sesame seeds and serve hot.
Instant Pot Thai basil chicken is now ready.