Arrange the white fish fillets in a single layer in a microwave-safe baking dish.

Season the fish fillets with salt and pepper.

Cover the dish tightly with microwave-safe plastic wrap.

Microwave the fish at high power (100%) for 3 minutes, or until it is opaque and just cooked through.

Carefully remove the plastic wrap to avoid steam burns.

Pour off any liquid from the dish.

Keep the fish warm, covered loosely.

In a microwave-safe glass measure, combine vegetable oil, julienned gingerroot, and julienned scallion.

Microwave the oil mixture at high power (100%) for 1 minute.

Add sesame oil to the mixture and let it cool slightly.

Pour the scallion-ginger oil over the steamed fish fillets.

Serve the fish sprinkled with soy sauce and white-wine vinegar to taste.