For the toppings 1/2 onion lettuce spring onion tomatoes watercress shiso perilla leaves ponzu
Take the meat out of fridge and leave it to rest at room temperature. Heat a frying pan. Lightly brush the beef with vegetable oil and season with salt and pepper. Sear the meat on each side until browned evenly.
Clean the excess oil away from the pan and add mirin, sake, and sugar and cook for a few minutes. Add soy sauce and continue cooking for a further 3-5 minutes stirring occasionally. Leave it to cool and put the meat and sauce in a resealable bag and leave in the fridge.
Prepare the vegetables of your choice. Slice the meat very thinly and serve with the vegetables on top. Pour the sauce over the meat and vegetables. Enjoy.