Step 1

In a large skillet with a tight-fitting lid, combine the vinegar, soy sauce, and ginger.

Step 2

Season both sides of the cod fillets with salt and pepper and place them in the skillet. Bring the liquid to a boil. Reduce the heat to a gentle simmer, cover, and cook, without turning, until the fish is almost but not quite opaque throughout, 6 to 8 minutes.

Step 3

Meanwhile, cut the green parts of the scallions into 3-inch lengths and then thinly slice each piece lengthwise into strips (reserve the white parts for another use).

Step 4

Carefully turn the fish, scatter the scallions over the top, cover, and cook until the cod is completely opaque throughout and the scallions are just wilted, about 2 minutes more.

Step 5

Gently shimmy a slotted metal spatula beneath the fillets and transfer to plates, leaving the aromatic cooking liquid in the skillet. Serve immediately. Originally published March 2, 2010.