Pre-heat the oven to the maximum temperature setting.
Place the T-bones on a piece of parchment paper in a roasting dish.
Season with salt and rub some olive oil all over the fish.
Cook in the oven for 8-10 minutes.
Take out of the oven and remove the skin.
Place 2 large tablespoons of the Anchovy and Rosemary butter onto each piece of fish and return to the oven for another 3-4 minutes.
Arrange the fish onto plates and drizzle over the juices. 
Garnish with rosemary and a wedge of lemon and serve.