The genius of tagliata is that you don't feel obligated to eat an entire steak, just take as many slices as you desire. Additionally, I assume I am not the only person who finds it difficult to menu plan for a family and whenever I assume there will be a fixed number there are always more. If you were making individual steaks, this might be an issue but with tagliata, I slice the steak on a large wooden board, strew the rocket over top and shave on the cheese and serve. The portioning sorts itself out. The peppery rocket counters the fat in the meat and adds freshness to the dish (one could also delude oneself that this is a type of "salad"). The key to a good tagliata is bringing the steaks to room temperature before cooking them. The grill or pan must be very hot to get a good crust on the outside while ensuring the meat is rare on the inside.