1. Using a food processor or blender, pulse the cilantro, parsley, garlic, onion and lemon juice until everything breaks down into smaller pieces and is more uniformly mixed. Stream in the olive oil while mixing on high. Continue processing until the sauce starts to look a little creamy. There will still be visible pieces of herbs but you don’t want long stringy pieces. Taste and adjust for salt and pepper. Let the chimichurri sit for 10-15 minutes before eating so the flavors can mellow. It can also be made up to three days in advance and kept in the refrigerator but the color may start to dull.
2. Heat a cast iron skillet over medium-high heat. Pat the chicken dry and season with salt and pepper on each side. Drizzle 1 tablespoon of olive oil into the pan and sear chicken until it forms a deep golden crust approximately 5 minutes on the first side. (Don’t move it until you flip!). Once the first side has seared, flip the chicken and allow the second side to sear until the internal temperature reaches 160 degrees, approximately 4-5 more minutes. Remove from heat and if using, add ghee to the pan and swirl around the chicken, using a spoon to drizzle some on top.
3. Allow the chicken to rest for 5 minutes before slicing and serving with the chimichurri sauce.
4. Reserve extra chimichurri sauce to use on other roasted vegetables, meats, etc.