In a mixing bowl, whisk together stock and mushroom soup; set aside.
Spray pot of pressure cooker with cooking spray. Add rice, onions, and mushroom soup mixture from bowl. Stir.
Brush chicken thighs with melted butter. Season with sea salt, fresh ground black pepper, thyme, and garlic.
Arrange chicken on top of the rice.
Close and lock lid, set pressure cooker to "rice", and press "start/stop".
When done, natural release for 15 minutes, then do a quick release to make sure all pressure is released before opening lid. Carefully open lid. Garnish with parsley. Serve hot.
