First, wash the chicken thighs and use paper towels to dry them. Next, heat some oil in the pot of an electric pressure cooker, like the Instant Pot, using the Sauté mode. Add the chicken and cook for approximately 6 minutes on each side until it becomes nicely browned. After that, remove the chicken from the pot and place it on a plate, while keeping the drippings in the pot for later use.
In the pot, sauté mushrooms, celery, and onion until they become tender, which should take approximately 5 minutes. Introduce garlic to the mixture and cook it until its aroma becomes noticeable, which usually takes around 2 minutes. Return the chicken to the pot and incorporate tomatoes and tomato paste. Season the dish with herbes de Provence and cover everything with water and bouillon.
Ensure the lid is tightly closed and locked. Follow the manufacturer's instructions to set the pressure to a high level. Give it approximately 10 to 15 minutes for the pressure to build up. Cook for a duration of 11 minutes.
To release the pressure safely, follow the quick-release method as per the instructions provided by the manufacturer, which should take approximately 5 minutes. Unlock and remove the lid cautiously, making sure to turn it away from yourself. Confirm the doneness of the chicken by using an instant-read thermometer inserted near the bone, ensuring it reads 165 degrees F (74 degrees C). Add red pepper flakes and black pepper according to your taste preference. .