Heat the oven to 375 degrees F and arrange your rack in the middle. Spread the walnuts on a rimmed baking sheet, and toast until golden, for about 8 to 10 minutes. Remove from oven until cool enough to handle then crumble slightly with your hands and set aside.

In a small bowl, mix together the coriander, cinnamon, 1 1/2 teaspoons of salt, and some freshly ground black pepper and rub into the chicken thighs. Set aside.

Heat the butter and oil in a large, heavy-bottomed saucepan or Dutch oven over medium-high heat. When the butter begins to foam, add the chicken to the pan, working in batches if you need to, so it’s in a single layer of chicken and not crowded. Cook the chicken thighs until they are golden brown on both sides, about 4-5 minutes per side, OR until golden and seared. Remove the chicken from the pan and set aside. Repeat with remaining chicken if you are making more.

Add the onions and mushrooms to the pan (don't clean your pan, you want all the crispy brown bits from the chicken), reduce heat to medium, season with salt and pepper and allow to cook, stirring occasionally, until the onions and mushrooms are golden brown, for about 5 minutes.

Add the chicken back to the pan and cook on low heat for another 10-15 minutes or so until chicken is no longer pink in center. Serve over fresh spinach and garnish with the walnuts, pomegranate seeds, and parsley.