Prep. time: 30 minutes
Cooking time: 90 minutes

An original recipe from Alain Ducasse, of the Restaurant Alain Ducasse, Paris

Preparing the bass and the jus 

1. In a cast-iron cocotte or Dutch oven, heat a little olive oil and a knob of butter. 
2. Add the fish head, cut in half, and brown. 
3. Sweat the minced shallots, garlic, thinly sliced fresh fennel, the leek, cut into strips, and the trimmings from the potatoes.
4. Deglaze with white wine and reduce by half. 
5. Add 500 ml (2 cups) stock from a pot-au-feu and 250 ml (1 cup) calf's foot jelly. 
6. Add the dry fennel, coriander seed, black pepper and Espelette chili. 
7. Cook over low heat for 15 minutes. 
8. Strain and set aside. 

Preparing the garnish 

1. Slice the potatoes into 3 mm thick triangles, about 2 cm high, allowing 15 per person. 
2. Heat the clarified butter to about 85°C.
3. Add the potato triangles and cook for about 45 minutes, being careful that the butter temperature does not rise above 85° C. 
4. Prepare the leeks and cut into thin strips, allowing 9 per person. 
5. Cook in boiling salted water and refresh in ice water. 
6. Slice the truffles into triangles as well, the same size as the potatoes, reserving the trimmings for the chopped truffle. 
7. In a large sauté pan, reduce a spoonful of the base with a knob of butter, a little truffle juice and some chopped truffle. 
8. Coat the potato triangles and leek strips in this reduced jus. 

Cooking the sea bass 

1. Skin and trim the fatty parts from the fillets of a 4 kg (9 lb.) sea bass. 
2. Cut into square-cut portions about 160 g (6 oz.), brush with oil and season with fleur de sel. 
3. Cook in a skillet over low heat, being careful not to let the fish brown. 
4. The fish will finish cooking in an earthenware dish. Line each dish with leeks and potatoes, add a small ladleful of the base, a little butter and 50 ml (3 tbsp.) truffle juice per person. 
5. Cook gently so that the flavors blend. 
6. Undercook the fish and finish the sauce with the cooking juices. 
7. Strain the cooking liquid, add a small ladleful of the base and reduce. 
8. Add some chopped truffle. Whisk in a little butter and season with a little truffle juice and some freshly ground pepper at the end. 

Finishing and presentation 

1. Arrange the leeks in a wreath, interspersing them with the triangles of potato and truffle (the truffles having been dipped into melted half-salted butter.) 
2. Spoon on the fish sauce. 
3. Place the pieces of sea bass in the center. 
4. Serve the remaining sauce in a small sauce boat.