Ingredients

2 (6-inch) pieces kombu

1 ounce harusame, soaked in water for 15 minutes

1/2 pound firm tofu, cut into 4 pieces

1/2 pound napa cabbage, sliced

1 negi, sliced on an angle into 2-inch pieces

3 1/2 ounces enoki mushrooms, trimmed and pulled apart

4 ounces shiitake mushrooms (about 8 pieces, stems removed)

1 teaspoon coarse salt

1 pound strip loin or rib eye, sliced paper thin (1/16 inch), for serving

1/2 pound spinach, stemmed, for serving

Sesame Dipping Sauce, for serving

Preparation

Place kombu on the bottom of a shallow 3 1/2-quart enameled cast-iron pot. Place harusame over kombu and top with tofu, cabbage, negi, and enoki and shiitake mushrooms, arranging each in a separate bunch in the pot. Add 8 cups of water and season with salt.

Cover pot and bring to a boil over high heat on a portable burner set on a dining table. Reduce heat to medium and simmer for 5 minutes.

Meanwhile, arrange meat, spinach, and sesame sauce on a serving platter. Uncover pot and add some of the meat slices, arranging in a single layer over other ingredients. Poach until rare or medium rare, 15 to 30 seconds. Dip into sesame sauce before eating. Add spinach and cook for 1 minute before eating. Continue cooking meat and spinach, adding more water as needed. Other ingredients in pot may also be eaten; dip in sesame sauce before eating.