The sugar in the teriyaki sauce will burn too quickly, giving the dish a burnt, bitter taste. Searing the fish on its own then adding the teriyaki sauce later ensures that each fillet is cooked to perfection without tainting its flavor.u003cbr/u003eu003cbr/u003eMarinating the salmon in teriyaki sauce works best if you are baking this dish. For searing, it's best to keep the sauce separate from the fish until you are ready to serve the dish.