Add the rinsed spinach to the instant pot, then add the onion masala on top.
Place the chicken on top of the spinach and sprinkle a big pinch of salt and pepper on top of the chicken (along with a pinch of any other spices you’d like, turmeric or cayenne).
Secure the lid, close the pressure valve and cook for 5 minutes at high pressure.
Naturally release pressure (or you can wait 10 minutes, then release pressure).
Remove the lid and use tongs to place the chicken thighs onto a cutting board and allow chicken to cool down for a few minutes. Meanwhile use an immersion blender to puree the contents of the pot and then stir in the spices listed under “add later.”
Chop the chicken into smaller pieces then add it back to the pot, stirring it into the spinach sauce.
Stir in heavy cream or ghee if desired – you can use as much or as little as you’d like (this will also lighten the color and make it more “restaurant-like”).