Preheat Instant Pot by pressing the "sauté" button.
Sautéing Veggies: Once IP is hot, add olive oil and then add chopped shallot, red and green bell peppers, scallions, garlic and sauté for 2-3 minutes.
Deglaze: MANDATORY STEP! Next add 1/4 cup of chicken stock to deglaze the bottom of the Instant Pot, making sure no bits and pieces are stuck to the bottom. This will ensure that nothing is stuck on the bottom to prevent BURN Warning. DO IT VERY WELL - BE GENEROUS WHEN DEGLAZING.
Next add remaining chicken stock, tomato paste, Cajun seasoning, onion powder, garlic powder and sea salt. Mix and stir to combine and to make sure nothing is stuck to the bottom.
Now add rinsed rice and make sure it's submerged into the liquid.
Add sliced chicken and season it generously with salt, pepper, Cajun seasoning and Oregano (or Italian Seasoning) right in the pot.
Then IMMEDIATELY close lid (IMPORTANT!) to avoid water from evaporating. Lock the lid and put valve to Sealing position.
Push Pressure Cook (this button is also called Manual on some models), set to High Pressure and set the time on the digital display for 8 minutes.
Pressure Release Method: When the time is up, use 10 minutes of natural pressure release: put the wet towel over the lid, move your face and body away from the lid and move the valve from Sealing to Venting.
If not using a towel, you will see a straight line of steam shooting vertically from the lid into the sealing, which perfectly normal. Wait until all the steam is out and until the red pin drops, then open the lid.
Shred the chicken strips with the fork and stir to combine with the rice. Taste an adjust the seasoning at this point.