On the Instant Pot, press on SAUTE then add oil and melt the butter. Season the chicken with salt and pepper.

When the butter is melted, add the seasoned chicken and brown it starting smooth side down. When it’s browned, flip and cook for 2 more minutes.

Remove the chicken onto a plate and set aside.

Add onion and saute it for 1-2 minutes, then add the garlic and cook for 30 seconds.

Deglaze the pot with the stock, and scrape off any bits stuck to the bottom of the pot. Switch off the SAUTE setting.

Add the thyme, mustard, and put the chicken back in.

Secure the lid and set the vent to SEALING. Select the PRESSURE COOK/MANUAL setting and set the cooking time for 6 minutes at high pressure. The Instant Pot will take around 5 minutes to come to pressure and start cooking. When the cooking program ends, quickly release the steam.

Remove the chicken onto a plate and set aside.

Press on SAUTE, and as the sauce starts simmering add cream and parmesan. Whisk until well combined and allow it to reduce a little (to your desired consistency).

Add the spinach leaves, and let them wilt. Add the chicken back in, spoon the sauce over the chicken and serve!