Baked hake with a Mediterranean crust

Ingredients

• 4 x 180g pieces of hake fillet, skinned and pin-boned
• 3 tsp chervil
• 4 tomatoes, cut in half then cut into quarters
• 1 red onion, chopped finely
• 50 g black olives
• 25 g sun-dried tomatoes
• 25 g pine nuts
• 75 g unsalted butter, softened
• 3 tsp chopped chervil
• 1 pinch saffron
• 50 g mature cheddar, grated
• 125 g rapeseed oil
• 60 ml white wine vinegar