REMOVE STEAK FROM REFRIGERATOR TO BRING TO ROOM TEMPERATURE. SEASON WITH SALT AND PEPPER. CHOP LEEKS AND SAUTÉE IN PERKY PISTACHIO OIL UNTIL SOFTENED. TURN OFF HEAT AND ADD A FEW TEASPOONS OF WHOLE GRAIN MUSTARD. SET ASIDE AND GRILL OR PAN FRY THE STEAK TO YOUR LIKING. LET SIT FOR SEVERAL MINUTES TO ALLOW THE JUICES TO REDISTRIBUTE, THEN CUT INTO THICK SLICES AGAINST THE GRAIN. TOP WITH MUSTARD AND LEEK, DRIBBLE PERKY PISTACHIO OIL FOR EXTRA NUTTINESS, AND ACCOMPANY WITH SIDE DISHES OF YOUR CHOICE.