Pan-Roasted Flathead with Celery Purée and Lentils – Truffle Jelly and Madeira Sauce

Celery Purée

• 20 g (¾ oz) duck fat
• 2 celery stalks, finely sliced

To make the celery purée, heat the duck fat in a saucepan. Add the celery and sweat over gentle heat with the lid on. When the celery is cooked, add the thyme and chicken stock, then the cream, and reduce until thickened. Remove the thyme. Season to taste and then purée to a paste in a blender. Pass through a fine-mesh stainless-steel sieve.

Heat some clarified butter i