1 Salt chicken thighs on both sides and let rest while you prepare the sauce.
2 If using whole cumin and coriander seeds, lightly toast the whole cumin and coriander in a small skillet on medium heat, until fragrant. Put into a mortar and pestle and grind until powdery.
3 Make the chermoula sauce: Put 4 cloves garlic, parsley, cilantro, salt, cumin, coriander, paprika, and lemon zest in a food processor. Pulse several times. With the motor running, slowly add in 1/2 cup of olive oil, then the lemon juice. Process until you have a smooth paste. You should have almost a cup of chermoula sauce.
4 Brown chicken thighs in skillet: Heat 1 Tbsp olive oil on medium high heat in a large cast iron pan and preheat oven to 350°F. Pat dry the chicken pieces and place them skin side down in the hot pan. Let them cook until deep golden brown, about 5 to 6 minutes. Then turn them over and cook a few minutes more.
5 Drain excess fat: Because you are working with skin-on thighs, you will likely render quite a bit of fat. Remove the chicken from the pan and pour off any excess fat. (Do not pour down the drain unless you want to clog your drain pipes.) Return the chicken to the pan.
5 Spread chermoula on chicken, bake in oven: Spread most of the chermoula sauce on both sides of the chicken thighs, reserving 1/4 cup of the fresh sauce to add later.
With the chicken skin-side up, put the skillet in the 350°F oven for 10 to 15 minutes, until the thighs are cooked through and the temperature near the bone is 165°F.
6 Spoon remaining sauce over chicken: Stir the reserved fresh chermoula sauce in with the pan sauce. Spoon sauce over the chicken to serve.
Serve with couscous or with basmati rice for a gluten-free option.