Preheat oven to 400°F.
Arrange the salmon pieces in a 9×13 inch baking dish. In a small bowl, whisk together the butter, maple syrup, mustard, and soy sauce. Pour over salmon. Sprinkle a pinch of freshly ground pepper.
Bake for about 15 to 20 minutes or until salmon flakes with a fork. Serve immediately.
*** Try this recipe on other fish such as tilapia, pickerel, or snapper. Alter the cooking time depending on the thickness of the fillets.