Rub London broil with olive oil and then coat generously with the dry rub. Let stand for about 15 minutes at room temperature.
Preheat a grill pan over medium-high heat.
Place meat on grill and grill for about 5 minutes on each side for medium-rare. Remove from heat and let rest for 5 to 10 minutes before slicing on the bias.
Mix all ingredients together thoroughly in a small bowl.