Fish Seasoning: Place ingredients in a bowl and mix to combine. It will keep for months in an airtight container. This quantity is enough for 750g / 1.5lb fish (serves 4 people)
Season fish: Sprinkle Seasoning on both sides of fish. Lightly rub to spread Seasoning.
Cook fish in two batches: Melt 30g / 2tbsp butter in large non-stick skillet over medium high heat. Cook fish until golden on each side (see Cook times below). Remove to a plate.
Cook remaining fish: Melt remaining butter in skillet and cook remaining fish.
Rest: Rest fish for 3 minutes before serving with extra butter sauce (see next step).
Extra butter sauce (optional): Add extra butter into pan over medium heat and melt until foaming. Drizzle over fish when serving.
