Kasai Fillet Steak Donburi with Soy-Cured Egg Yolk

Charcoal-kissed fillet steak over steaming Japanese rice, lacquered in soy glaze and crowned with a silky soy-cured egg yolk. Finished with toasted sesame and spring onion — rich, smoky, and unapologetically indulgent.

Method

Cook the Rice

1. Rinse rice under cold water until mostly clear.

2. Cook with 360 ml water (rice cooker or covered pan).

3. Rest 10 minutes, then fluff.

4. Stir through rice vinegar and sesame oil lightly. Keep warm.

Prepare the Kasai Grill

• Set up for high direct heat.

• Allow the coals to ash over but remain very hot.

• Lightly oil the grill bars.

Fillet is lean, so you want fierce heat for quick caramelisation without overcooking.

Cook the Steak

1. Bring steaks to room temperature (30–45 mins).

2. Pat dry and season generously with salt and pepper.

3. Lightly oil the steak, not the grill.

Grill over high heat:

• 2–3 minutes per side for medium-rare (internal temp ~52–54°C).

• Add 30–60 seconds per side for medium.

• Finally take some coal and roll it over the top for a really smoky finish

In the final minute, brush both sides with the soy glaze and allow it to lacquer and caramelise slightly. Avoid burning — soy can catch quickly.

Rest 5–7 minutes.

Assemble the Donburi

1. Divide hot rice between two deep bowls.

2. Slice steak against the grain.

3. Lay over rice.

4. Spoon over any resting juices and a final light brush of glaze if desired.

5. Place a cured egg yolk in the centre.

6. Finish with sesame seeds and spring onions.

Finishing Touch

Just before eating, break the yolk and let it run into the hot steak and rice — it forms an umami-rich sauce without any extra effort.

Optional Enhancements

• Add a quick pickled cucumber for acidity.

• A small knob of smoked butter melted over the steak during resting works beautifully on a kasai grill.

• If you like heat, a drizzle of chilli oil is excellent.