From book Japanese Soul Cooking, Tadashi Ono and Harris Salat.
SERVES 4
1 medium Spanish onion (about 12 ounces), peeled, cut in half lengthwise, and sliced ½ cup dashi ½ cup sake ½ cup mirin ½ cup soy sauce 8 eggs 4 fillets cooked tonkatsu, each fillet cut into ½-inch slices 6 cups cooked Japanese white rice 8 sprigs mitsuba, stems and leaves coarsely chopped (I used parsley)
Add the onion, dashi, sake, mirin, and soy sauce to a saucepan and bring to a boil over medium heat. Cook for about 5 minutes, until the onions soften.
Break 2 eggs into a bowl and lightly beat the eggs, no more than 10 times. You want part of the yolk and whites to be lightly mixed, while other parts are still separated. Set aside.
To prepare the katsudon one serving at a time, pour one-fourth of the sauce and onions into a small skillet. A 6-inch skillet works great. Place a sliced tonkatsu fillet in the sauce. Place over high heat and cook for about 30 seconds.
Pour three-fourths of the egg mixture over the tonkatsu, onions, and sauce. Do not mix. Cook for about 1 minute, then add the remaining one-fourth egg over the ingredients in the skillet.
Cover the skillet and cook for 30 seconds more. Turn off the heat, and let the katsudon rest, covered, for 1 minute.
While the katsudon is resting, scoop 1½ cups of the cooked rice into a serving bowl. When the katsudon is ready, uncover, and slide entire contents out of the skillet to rest on the rice.
Tilt the skillet and use a spatula if necessary; the katsudon should slide out easily.
Garnish with mitsuba and serve immediately. Repeat for the remaining servings.