In a small bowl mix together the spice rub ingredients.
Drizzle 2 teaspoons of oil over the lamb chops and use your hands to rub the oil into both sides of the meat. Then rub the spice mixture onto both sides. Allow the lamb chops to sit and absorb the flavors of the spice mixture while you prepare the tahini-yogurt sauce.
Using a whisk or fork mix together all the ingredients for the tahini yogurt sauce. Add ice water, 1 tablespoon at a time, until sauce is a thick but spreadable consistency. Set aside. Note: If you prefer to drizzle the chops with the sauce rather than set them on a bed of sauce, thin with ice water until desired consistency.
Heat 2 teaspoons of oil over medium-high heat in a 12-inch cast iron skillet or heavy-bottomed pan. Once hot add chops and cook for 3-4 minutes per side for medium-rare or until the temperature on an instant-read thermometer reads 125 degrees Fahrenheit, for medium-rare, or 130 degrees Fahrenheit for medium.
Transfer the cooked lamb chops to a platter and loosely tent with foil. Let rest for 10 minutes.
Meanwhile, spread the tahini yogurt sauce on a large plate or platter. After the chops have rested, arrange them on top of the sauce and sprinkle with chopped parsley and crushed chili flakes if using. Serve and enjoy!