In an Instant Pot or other electric pressure cooker, turn on the “Saute” function. When the Instant pot reads “hot” on the display, add the olive oil.
Season the chicken thighs with salt and pepper, then add them to the hot Instant Pot in a single layer, working in batches if needed. Sear the chicken thighs until browned on each side, then remove from the pot.
Add the onion, carrot, red pepper, and garlic to the pot, adding more olive oil if the pot seems a little dry. Saute for 1-2 minutes, until slightly softened. Season with salt and pepper.
Add the harissa paste, stirring to coat. Saute for about 30 seconds.
Add the chicken stock to the pot, and scrape up any browned bits. Add the chickpeas, stir to combine.
Pour the crushed tomatoes over top of the chickpeas and vegetables. Place the seared chicken thighs on top of the tomatoes. Press the “Cancel/Keep Warm” button.
Press the “Manual” or “Pressure Cook” button, and set the timer to 10 minutes. Put the lid on, and make sure the valve is set to “sealing”. When the timer is done, manually release the pressure.
Use two forks to shred the chicken thighs. (I do this directly in the Instant Pot).
If the stew seems too thin, press the “Saute” button and bring to a simmer until it reaches your desired thickness. Stir in the oregano and raisins. Add the ras al hanout to the stew, and more harissa if you’d like more spice.
Serve immediately with flatbread or over couscous.