Drizzle steak (should be at room temp) with olive oil. Rub steak with chopped garlic and rosemary leaves and let sit for a half hour to an hour.
Remove rosemary and garlic from steak and season both sides with a generous amount of salt and freshly cracked pepper. Heat skillet to medium/high heat and add butter with a drizzle of olive oil until it starts to bubble.
Add your steak to the pan and cook for about 3 to 4 minutes on each side for medium rare. Add rosemary and garlic back into the pan for extra flavor. Remove steak from heat and let rest for about 5 minutes before slicing.