Combine the melted butter, vegetable oil, Worcestershire sauce, honey mustard sauce, dark brown soft sugar and garlic granules in a large bowl. Whisk to combine. Reserve 2 tablespoons marinade for basting. Place the salmon in a shallow dish and pour the remaining marinade over. Cover and chill for 45 minutes.
Preheat the grill and set the grill pan about 12.5cm from the heat source.
Grill salmon for 12 minutes, brushing occasionally with the reserved marinade. Salmon is done when it is glazed from the marinade and flakes easily with a fork.