With a large chef's knife, chop salmon using quick, even, straight-up-and-down motions (do not rock the knife through the fish or it will turn mushy). Continue chopping, rotating the knife, until you have a mass of roughly 1/4-inch pieces. Transfer to a large bowl. Add scallions, egg, ginger and oil; stir to combine. Form the mixture into 4 patties. The mixture will be moist and loose, but holds together nicely once the first side is cooked.

Coat a large nonstick skillet with cooking spray and heat over medium heat for 1 minute. Add the patties and cook for 4 minutes. Turn and continue to cook until firm and fragrant, about 3 minutes. Spoon the reserved wasabi glaze evenly over the burgers and cook for 15 seconds more. Serve immediately.

Ingredient note: Wasabi powder, when mixed with water, becomes the green paste most of us know from sushi restaurants. The powder is available in jars in the Asian aisle of most supermarkets or in almost all Asian markets. Store at room temperature for up to 1 year.To skin a salmon fillet: Place it on a clean cutting board, skin side down. Starting at the tail end, slip the blade of a long, sharp knife between the fish flesh and the skin, holding the skin down firmly with your other hand. Gently push the blade along at a 30 degree angle, separating the fillet from the skin without cutting through either. Or have your fishmonger do it for you.