Season the chicken with salt, pepper and about 2 teaspoons of the spice mix. Be sure to season them well on both sides.
In a large cast iron pan, heat 1 tablespoon of oil over medium heat. Add the chicken and cook about 3-5 minutes per side until nicely browned. You may need to do this in batches, depending on the size of your pan. You don’t want to crowd the chicken or it won’t brown. If you’re using bone-in, skin-on chicken at a couple more minutes per side.
Once the chicken is golden brown on both sides, remove from the pan and set aside. With the pan still on medium heat, add the coconut milk and whisk in the harissa. If it starts to splatter a bit, turn down the heat until it’s a nice low simmer.
Return the chicken and continue to simmer until the chicken is fully cooked and the sauce is thickened. Depending on the thickness of your chicken this could take about 15 minutes. If you’re using bone-in, skin-on it will probably take about 30 minutes for the chicken to be fully cooked.
Sprinkle with the parsley and serve immediately.