Preparation
Heat grill, cut side of salmon into 4 equal pieces. Whisk together the mustard, soy sauce, olive oil and garlic in a small bowl. Drizzle half of the marinade onto the salmon and allow it to sit for 10 minutes.
Place the salmon skin side down on the hot grill, discard the marinade the fish was sitting in. Grill for 4 to 5 minutes, depending on the thickness of the fish. Turn and cook for another 4 to 5 minutes. Spoon reserved marinade on top, allow fish to rest for 10 minutes. Remove the skin and serve warm, room temperature or cold.