Thinly slice the meat using a sharp knife, place in a bowl. Add the oil and cheese, mix carefully, then season. Layer the meat and shape into 4 burgers using a metal cutter (approx. 7.5 cm in diameter), cover and marinate in the fridge for approx. 1 hr.
Heat the clarified butter in a frying pan. Briefly sauté the garlic and rosemary, add the burgers, fry for approx. 1 min. on each side (the burgers must remain raw on the inside).