4: Pour 3 tablespoons olive oil into a frying pan on medium heat. When good and hot, add the chopped shallot, salt and pepper. Cook for 1 minute without colouring.
5: Add the leeks and cook until soft, stirring regularly. Set aside.
7: Put into a blender bowl or goblet: 150 ml liquid cream, 1 teaspoon lemon juice, salt, pepper and the coriander leaves. Blend until well mixed. Refrigerate until needed.
8: Preheat the oven to 360°F (180°C). Prepare the fillets of sea bass: carefully remove the skin and any remaining bones. Rinse and dry the fillets. Salt and pepper on both sides.
9: Lay a sheet of cooking parchment in front of you. Spread a thin layer of the julienne of leeks in the centre.
10: Lay a fish filet on top and pour some of the coriander cream sauce over.
11: Fold up into a parcel. Make all the papillotes like this.
12: Bake for 20 minutes.
13: It is always best to serve papillotes still sealed. Your guests can then open the little parcels themselves and enjoy the wonderful aromas that escape.
Remarks
If you have some of the coriander cream sauce left over after making up the papillotes, serve it to accompany the fish, but well chilled, as the coriander has more flavour when it is fresh and raw. You can, of course, use other fish instead of sea bass: whiting, sole, etc.