Preheat your oven to 425ºF with the oven rack in the middle. Line a rimmed baking sheet with parchment paper (for easy cleanup), and place a baking rack on top of the parchment paper inside the rimmed baking sheet.

Preheat a cast iron skillet over medium heat for 5 minutes. While the skillet is heating, pat the chicken thighs completely dry with a paper towel. Season both sides with salt + pepper.

Add the olive oil to the pan, and cook the chicken thighs skin side DOWN for 8-10 minutes over medium heat. Do not move the chicken thighs around in the pan. By cooking them over medium heat for a longer amount of time, they skin gets golden brown and ultra crispy.

When the thighs are crispy and golden brown, transfer them to the rimmed baking sheet skin side UP. Finish roasting in the 425ºF oven for another 10-15 minutes until the thighs have in internal temperature of 165ºF using a meat thermometer.

While the thighs are roasting in the oven, remove all but 1 tablespoon fat from the same cast iron skillet. Over medium heat, add the mushrooms, onion, garlic, thyme, salt and pepper. Cook until the vegetables are soft and turning golden brown, about 5-8 minutes, stirring occasionally and scraping up all the brown bits from the bottom of the skillet.

In a measuring cup, whisk to combine the chicken stock and arrowroot powder. Add to the pan with the cooked mushrooms and onions. Heat over medium until bubbling, 3-5 minutes. The heat will activate the arrowroot powder to thicken the sauce.  Remove the skillet from the heat. Add in the cashew cream and lemon zest, and stir to combine. Add the chicken thighs back in to the pan.

Serve warm. Amazing with my Whole30 + Keto Mashed Cauliflower or Whole30 Mashed Potatoes!

Leftovers will keep in an airtight container refrigerated for 5 days.