Generally, fish fillets that are one-inch thick will be cooked through in 8 minutes. Adjust the cooking time to match the fillets you are using.
1 ½ pounds Tilapia, Cod, or Halibut fillets (about 1 inch thick), skin removed, cut into 4 serving pieces
½ cup Sake or White Wine
¼ cup Water
1 tablespoon Soy Sauce
4 Scallions, cut half lengthwise, white and pale-green parts (thinly slice the dark green parts for garnish)
1 ripe Tomato, cut in thick slices
3 heads Baby Bok Choy, cut in half lengthwise
1 small piece fresh Ginger, sliced into 4 rounds
1 tablespoon dark Sesame Oil
In a large skillet with a cover, combine the sake, water, and soy sauce. Lay the scallions, tomato slices, bok choy, and ginger down in the bottom of the skillet, so they make a bed for the fish to rest on. Bring the liquid to a boil, cover, and cook for 2 minutes, to let the vegetables soften a bit.
Lay the fish fillets on top and sprinkle lightly with salt and drizzle with the sesame oil. Cover and continue to cook, over medium-low, until the fish is opaque and flakes when pierced with a fork, about 6 to 8 minutes, depending on the thickness.
Serve the fish with the braised vegetables and resulting sauce spooned over, discarding the ginger slices. Garnish with fresh scallion greens and eat immediately.