Pre-heat oven to 450 Fahrenheit and place 12-inch cast iron skillet in the oven to heat up.
Use a paper towel to pat both sides of salmon dry. If the skin is wet, it won't get crispy.
Season the salmon skin with kosher salt.
Carefully, remove hot pan from the oven and melt ghee in the pan.
Add salmon, skin side down, to the pan. You want to hear a sizzling sear when it hits the pan. Season top of salmon with a little more salt and black pepper and place in the oven for about 15 minutes.*
Once the salmon is opaque and flaky and opaque, it's ready to serve. I usually just stick a fork in and twist to make sure my salmon is done.
Serve and enjoy!
*General rule of thumb is to cook for 4-6 minutes per every 1/2 inch of thickness. So be sure to adjust cook time as needed.