Heat a sauté pan on medium. Once that heats up, add 1 tablespoon oil and after that heats up, add chicken skin side down. (You may have to do this in two batches). Sauté for 3 minutes, flip and cook for an additional minute. Remove chicken and set aside
Plug the IP in and press the sauté button. After it has heated up, add one tablespoon of oil and add the onion and red and green peppers. Sauté for 3 minutes
Add mushroom, salt and pepper and sauté for 1 minute
Add chicken, crushed tomatoes, chicken broth, sherry, oregano, basil, bay leaf and garlic paste
Seal the IP, make sure the venting knob is set to sealed and push the pressure cook button and set the timer to 13 minutes. It will take an additional 10 - 15 minutes for the pressure to build until the timer starts to count down.
Once the pressure cooker beeps that it is done, either let the IP release pressure naturally or put on an oven mitt and carefully release the pressure, by tapping the knob over and over for a quick release.
Transfer the chicken and gravy over to a serving dish or serve out of IP
Ladle some chicken cacciatore over some pasta or rice along with some vegetable