Poach the fish fillets in the milk for about 15 minutes until the fish flakes. Drain the fillets and reserve the milk.

Peel the skin off the fish and remove any bones. Process the fish, potatoes, fennel, garlic, eggs and butter in a food processor fitted with a metal blade.

Add 30ml/2 tbsp of the reserved cooking milk and season to taste with salt and pepper.

Chill in the fridge for about 30 minutes, then shape into 20 croquettes with your hands.

Mix together the breadcrumbs and sesame seeds.

Roll the croquettes in the mixture to form a good coating. Heat the oil in a large heavy-based saucepan and deep-fry in batches for about 4 minutes until golden brown. Drain well on kitchen paper and serve hot.