Lamb topside with sweetbreads, potatoes salardaises and sauce Périgueux

There are a good few elements in this dish, but the sauce and the potatoes can be made a day in advance, so start with these

For the sauce, heat the vegetable oil in a saucepan over a medium heat. Add the shallots, garlic, thyme and mushrooms with a pinch of salt, and cook for around 5-8 minutes until soft but without colour

Add the wine and port, bring to a simmer and leave to reduce until nearly dry

While the sauce simmers, start preparing the potatoes. Bring a salted pan of water to the boil and cook the potatoes for around 10 minutes, or until parboiled. Drain, then once cool enough to handle, peel and grate the potatoes into a bowl – you will need around 380g of grated cooked potato in total

Fry the diced bacon until starting to crisp, then add this to the bowl of grated potato. Soften the finely chopped shallots in a spoonful of the duck fat and a dash of oil for around 3-5 minutes until soft, then add these too

Mix the rest of the ingredients into the potato mixture using your hands, ensuring the shredded lamb (if using) is evenly mixed throughout. Set aside

Once the wine and port have reduced in the sauce, pour in the lamb stock, bring to the boil, then turn down to a simmer. Skim off any scum that rises to the surface, then leave to simmer until it has reduced down to a sauce consistency

While the lamb stock reduces, divide the potato mixture into 6. Cover and leave in the fridge until ready to cook tomorrow

Once you’re happy with the consistency of the sauce, strain it through a fine sieve into a container and add the minced truffle. Cover and leave to infuse for 30 minutes, then place in the fridge to reheat before serving

The next day, begin with the vegetables. Place the garlic cloves – still in their skins – in a small pan and cover with the duck fat. Gently cook over a low heat for about 1–2 hours, or until the garlic cloves are completely soft. Drain them from the fat and chill in the fridge until ready to serve. Any leftover confit garlic and duck fat should be kept refrigerated and used within two days

Place the peeled baby onions in a saucepan and cover with cold water or, if you have it, chicken stock. Add a pinch of salt, then bring to the boil. Simmer for 2 minutes, then drain and leave to cool. Set aside

Take the lamb topside out of the fridge at least 1 hour before you plan to cook it to ensure it’s at room temperature

To prepare the sweetbreads, place them in a pan and cover with cold water. Bring to the boil, then drain and refresh in cold water immediately. Peel off any fat or membrane from the sweetbreads, then break or cut them into 3cm chunks. Pat dry and set aside

Preheat an oven to 180°C/gas mark 4. Place a large ovenproof frying pan over a high heat and add a dash of vegetable oil. Liberally season the lamb topside all over with salt and pepper, then add it to the pan and sear on all sides until brown all over. Add the butter, garlic and thyme, then continue to cook, basting constantly, for 3-4 minutes

Transfer the topside to the oven and cook for a further 12-15 minutes, basting the meat a few times throughout. You’re looking for an internal temperature of 45°C, so a skewer inserted into the centre should be just warm as you touch your lip to it. Once it’s cooked through, leave to rest somewhere warm while you prepare the final elements. Leave the oven on so you can give the lamb a quick reheat just before carving

Bring a small pan of vegetable oil to 180°C. Mix together the flour, sparkling water and a pinch of salt together to create a thin batter for the anchovies. Gently reheat the sauce ready for serving

Pan-fry the onions in a little oil and butter until golden, then drain off the fat and set aside somewhere warm

Place a frying pan over a medium-high heat. Use a metal ring to shape the potato mixture into a compact disc around 1.5cm in thickness inn the pan, then pan-fry the potato patties for around 4 minutes on each side until golden brown. You shouldn't need any additional fat in the pan due to the duck fat in the mixture. Keep warm

To cook the sweetbreads, place a frying pan over a high heat and add a splash of oil. Once smoking hot, season the breads with salt and cook until golden brown all over. Add the butter and baste for 1 minute, then drain off the fat, return to the heat and add the vinegar. Continue to cook until the sweetbreads are glazed and the vinegar has reduced completely, then set aside somewhere warm

To cook the anchovies, dip them into the batter then deep-fry in the hot oil for a few minutes until crisp. Drain on kitchen paper and set aside

To serve, add a potato patty to the centre of each plate. Arrange 3 garlic cloves, 3 pieces of sweetbread and 5 onions. Return the rested lamb and the garlic cloves to the oven for a minute to reheat, then carve the lamb into thin slices and add slices to each plate on top of the potato. Spoon the sauce around the lamb, then garnish with crispy anchovies and sprigs of sea fennel. Serve any remaining sauce on the side