Roast Lamb Kidney with Celeriac Purée and Truffle Vinaigrette

For the kidneys

• 1 whole veal or beef kidney in suet, cleaned and fat trimmed
• 1 tbsp vegetable oil
• 3 garlic cloves
• 1 bay leaf
• 2 thyme sprigs
• 50g/1¾oz butter
• 1 tbsp Armagnac brandy
• 2 tbsp dark veal or beef stock
• salt and freshly ground black pepper

For the celeriac purée

• 500ml/18fl oz whole milk
• 1 celeriac, peeled and chopped
• 25g/1oz butter

For the truffle vinaigrette

• 1 black truffle, finely chopped
• 1 tbsp sherry vinegar
• 3 tbsp vegetable oil
• 1 shallot, finely chopped
• ½ tsp Dijon mustard
• 2 tbsp chives, finely chopped
• truffle oil, to taste

Method

1. Preheat the oven to 200C/180C Fan/Gas 6. Season the kidney with salt and pepper. Heat the oil in a frying pan and sear the kidney on all sides until nicely browned. Transfer to a roasting tin with the garlic, bay leaf and thyme and roast for 10 minutes. Reduce the oven to 180C/160C Fan/Gas 4 and return the kidney to the oven for another 10 minutes, or until golden on the outside. Remove and allow the kidney to rest before slicing. Meanwhile, add the butter, Armagnac and stock to the frying pan and deglaze over a medium heat for a few minutes to form a glossy sauce.

2. For the celeriac purée, place the milk and chopped celeriac in a large saucepan. Gently simmer until the celeriac is very tender. Stir in the butter, season with salt and pepper, then blend until smooth and creamy.

3. To make the truffle vinaigrette, combine the chopped truffle, sherry vinegar, vegetable oil, shallot, Dijon mustard and chives in a small bowl. Adjust the seasoning and add truffle oil to taste. Stir in some of the deglazed pan sauce if you like, to enrich the vinaigrette.

4. To serve, spoon the warm celeriac purée onto warmed plates, arrange slices of rested kidney on top and drizzle with the truffle vinaigrette. Serve immediately while everything is hot and fragrant.