Wash the chicken and pat dry with paper towels, then season with salt and pepper.
Preheat the pressure cooker pot on sauté mode. When the display reads hot, add the oil, then add the chicken thighs in a single layer, cooking for 5 minutes on each side, or until browned. Transfer the chicken to a plate and set aside.
Add the onion, bell pepper, and mushrooms and sauté until softened, 4 to 5 minutes. Add the garlic and herbes de Provence and cook for 1 minute, or until fragrant.
Pour in the wine & deglaze the pot, scraping up the browned bits from the bottom with a wooden spoon and stirring them into the liquid. Cook until the wine is reduced by half.
Set the chicken on top of the contents of the pot, then pour in the tomatoes and their juices and the tomato paste.
Secure the lid and cook on high pressure for 12 minutes, then allow the pressure to naturally release, about 10 minutes. Open the vent at the top and remove the lid.
Stir in the olives and red pepper flakes (if using). Taste and adjust the seasonings as desired.
Serve over pasta, mashed potatoes, spaghetti squash, or polenta, garnished with basil or parsley.
