Step 1

To make the marinade add the soy sauce, cooking sake and mirin to a small bowl and stir. Transfer the marinade mixture to a pan and bring to a gentle simmer for a few minutes before adding the chopped spring onion and garlic, set aside to cool (your spring onion and garlic are to remain quite raw).

Step 2

Season your fillet beef with salt and pepper and leave it to rest for about 10 minutes at room temperature. Grab a medium-sized frying pan, add a splash of sesame oil and on medium heat evenly sear your beef for one minute on each side, it should be rare on the inside.

Step 3

Let it rest on a chopping board for 5 minutes then slice your fillet very finely and lay on a long plate. Pour the marinade sauce over the beef and serve with a small dipping bowl of ponzu soy sauce. You can also cover and leave it to chill in the fridge if you want to serve it cold with a higher marinade infusion.