Concentrated turbot essence

For 15 glasses

600 g of very fresh unwashed turbot heads
1 leek
concassée made with 3 tomatoes
1 sprig of basil
500 ml of fish stock
 

Stew the clean turbot heads with the finely chopped leek and the sprig of basil; cook on a high heat for about 5 minutes and add a little concassée, so that the colour of the concetrate stays grey. Cover with hot stock. When the concentrate starts to simmer, take off the heat and filter, pressing the heads firmly.

Serve the concentrate in the glasses to accompany turbot-based dishes.