A little tip: Never use an aluminum cooking utensil for this kind of recipe.

1. Trim the leek, cook in salted water and cool;
2. line the interior of a terrine with the cooked leek leaves and set aside;
3. in a saucepan, heat the olive oil and sauté the garlic, onion, carrot, the rest of the leek and the fennel for 7 minutes; add the tomatoes and cook 5 minutes longer;
4. add the fish stock, the saffron, thyme, salt and cayenne; bring to a boil;
5. add the monkfish and cook 2 minutes, add the remaining fish; cook for 4 minutes over low heat;
6. place the fish into the terrine with the vegetables;
7. dissolve the gelatin sheets in the broth; correct the seasoning and pour over the ingredients in the terrine;
8. cover with leek leaves and refrigerate for 12 hours;
9. serve in slices.