Pre-heat the fan assisted oven to 170C / 190C / 375F / gas 5.

Rinse and pat the fish dry, cut 3 incision in each side and place in a baking tray.

In a small bowl mix together the olives, half of the oregano, garlic, anchovies and a splash of olive oil to bind.

Rub the the olive mixture on both sides of the fish and add the tomatoes and remaining oregano to the baking tray.

Cut the lemon in half and squeeze the juice from one half over the top of the fish. Cut the remaining half into thin slices and place them in the cavity where the sea bass was gutted. Drizzle a generous proportion of olive oil over the fish and tomatoes and season well with salt.

Bake fish for for 25 minutes for smaller fish or up to 35 minutes for a large fish, or until the flesh is white and firm to touch.

Whilst the fish is baking mix together all the ingredients for the tahini sauce adding a couple of tablespoons of water to give you a smooth sauce. Season with salt.

When cooked, scatter with fresh oregano and serve with the tahini sauce to drizzle over.

Serve with new potatoes or crusty white bread.