Begin by preparing the sauce, which can be left to simmer without needing too much attention
The sauce can also be prepared up to two days in advance and gently reheated
In a large heavy-based saucepan, heat 1tbsp of oil
While the oil is heating, finely slice four of the shallots then throw them in to the pan along with the celery, carrot and four rashers of pancetta cut into lardon
Cook the vegetables of a medium-low heat for around five minutes until soft
It is important to make sure that the onions do not colour
Once the vegetables are soft, add the garlic and thyme leaves to the pan, increase the heat, stir and continue to cook for another minute
Next, add the wine to the pan and increase the heat to bring the liquid to a fast boil
Ideally, the wine should deglaze the pan and begin to reduce quite rapidly (avoid stirring this too much, or the wine will take far longer to reduce)
Once the wine has reduced by 2/3 and has a thick, syrupy texture, slowly add the stock and stir
Bring back to the boil and season with a generous pinch of salt and crack of pepper
Once the stock begins to boil, reduce the heat and simmer, uncovered, for approximately 45 minutes, until the sauce reduces and reaches a desired thickness
Again, avoid over-stirring, but ensure that the vegetables do not stick to the bottom of the pan and burn
One the sauce has thickened, strain the liquid into a clean pan and place over a low heat
Stir 50g of unsalted butter into the sauce, add the sugar (if necessary) then slowly stir 50-100ml of double cream into the sauce
Once the cream has been added, do not allow the sauce to boil
To Prepare the Celeriac Puree
Peel the celeriac and potatoes then cut into 1-inch cubes
Bring a saucepan of water to the boil and start by simmering the celeriac for 5 minutes
Add the cubed potatoes to the same pan and bring back to the boil
Cover the pan and simmer until the celeriac and potatoes are soft enough to break with a fork
Strain and briefly return to the pan over a low heat to evaporate any excess liquid
Meanwhile, gently heat 100ml of cream and 100g butter in a pan
As soon as the celeriac and potato is removed from the heat, begin to mash and slowly incorporate the cream and butter, then grate a little nutmeg into the puree
Continue to mash the ingredients together until a silk consistency is achieved
This can also be passed through a sieve or potato ricer to develop a smoother, more luxurious puree
To Prepare the ‘Burnt’ Onions
Heat a frying pan with 1tbsp of oil and 10g butter
Add the halved onions (flat-side down) and cook on a medium heat, undisturbed, for at least four minutes
Gently turn one of the onions to check whether the flat-side has coloured
This should be caramel-brown and will fall apart very easily, so be careful
Add a splash of balsamic vinegar to the pan, turn the rest of the onions over and reduce the heat
Cook on a low heat until the vinegar has reduced by at least half
Transfer the onions to a grill pan or roasting tray and place in the bottom of the oven on a low heat to keep warm
To Prepare the Peas
Heat the peas in a saucepan with 50g butter
Cover and cook slowly, ensuring that the peas do not stick to the bottom of the pan and burn
To Prepare the Liver and Bacon
In a clean frying pan, add eight rashers of pancetta and begin to cook slowly over a low heat
The fat from the pancetta will begin to render almost instantly, so it’s unnecessary to add any extra oil
Cook the pancetta until it begins to colour, but remove from the pan around 3-5 minutes before it reaches optimum crunchines
Transfer the pancetta to the tray at the bottom of the oven, with the onions, to continue cooking and keep warm
This will cook quickly, so be sure to keep an eye on it to prevent it from burning
Meanwhile, add a little oil to the pan with the pancetta fat and add 50g of flour to a plate and season with salt and freshly-ground black pepper.
Dredge the liver in the flour mixture and shake to remove any excess
Once the pan is “screaming” hot – add the liver to the pan
Ensure that the pan is not overcrowded, which may mean cooking the liver in batches
Leave the liver in the pan, without turning, over a medium-high heat for 2-3 minutes
Flip the liver, reduce the heat and cook for a further 1-2 minutes
Calves’ liver is best served pink, prevent any toughness or loss of succulence
Remove the liver from the pan and rest on a slightly warmed plate while you assemble the rest of the dish
To Assemble
Smear a heaped spoonful of celeriac puree to the centre of a warmed plate
Assemble the onions (‘burnt’ side up) around the puree then place the liver on top of the dish.
Finally, top each plate with two rashers of criss-crossed crispy pancetta and a spoonful of peas scattered around the dish)
(For presentation purposes: it is best to serve the sauce on the side – allowing diners to pour their own)