To spatchcock the chicken, place the whole bird breast side down on a cutting board and use your fingers to locate the backbone which should run all the way down from neck to tail. Use kitchen scissors or a sharp knife to cut along the right side of the backbone, and then cut all the way along the left side of it so that the backbone can be removed. Now flip the bird over and press down firmly on the breasts to flatten the bird. Rinse the inside of the chicken out and place it in a large baking dish or cast iron skillet. Pat the skin dry using a paper towel.
In a bowl stir together the softened ghee (or butter) and paprika, oregano, chili powder, optional garlic powder, salt and pepper. Once well mixed, use your hands to smear the cajun ghee/butter all over the skin of the chicken.
Place the chicken in the oven to bake for 40 minutes until a meat thermometer inserted into the thickest part of the breast registers 160º Fahrenheit. About half way through cooking spoon some of the liquid from the bottom of the pan overtop of the chicken before returning it to the oven to continue cook.
Once the chicken is done cooking, remove it from the oven and pour all of the liquid from the bottom of the baking dish into a small sauce pan on high heat. Place a large piece of tin foil over the roast chicken to keep it warm while it rests.
Add the minced garlic to the sauce pan with the liquid from the bottom of the pan and bring to a gentle simmer. Leave to simmer for 5-7 minutes until the liquid has reduced by half and then add in the lemon juice and parsley.
Carve the roast chicken and spoon the garlic cajun sauce drizzled over top.