Monkfish with mushrooms and fermented celeriac

You’ll need to ferment the celeriac and mushrooms for the sauce 3 weeks in advance, so start with this. Juice the celeriac and pass the liquid through a muslin cloth. Weigh the juice, then work out 2% of the weight and add that amount of salt. Pour into a sterilised jar to ferment in a warm place for 3 weeks, opening the jar daily to release the gas. You will need 75g fermented celeriac juice for this recipe

Pulse the fresh mushrooms into a coarse paste, then add 0.5g of salt. Place in a sterilised jar to ferment in a warm place for 3 weeks, opening the jar daily to release the gas. You will need 15g of the juice released from the mushrooms for this recipe

The day before you plan to serve the dish, brine the monkfish. Make a 4% brine by dissolving 40g of salt in a litre of water, then cooling. Trim the monkfish tail and submerge it in the brine for 8 hours in the fridge

Once brined, drain the monkfish tail and wrap tightly in cling film, forming a ballotine shape. Place in a vacuum bag and seal. Preheat a water bath to 48°C, then cook the monkfish sous vide for 30 minutes, or until the internal temperature reaches 43°C. Transfer the bag to a bowl of iced water to cool, then store in the fridge until ready to reheat before serving

For the dashi, bring the water to 70°C in a pan, then add the kombu. Remove the pan from the heat and leave to infuse for 1 hour. Remove the kombu and place the pan back on the heat, bringing it to 70°C once again. Add the mushrooms and bonito flakes, then remove from the heat and leave to infuse for 30 minutes. Pass the dashi through a fine sieve and chill

For the fermented mushroom sauce, add 75g fermented celeriac juice, 15g fermented mushroom juice, 75g of the dashi, the crème fraiche and the xanthan gum water to a Thermomix at 70°C. Blitz until smooth and, with the motor still running, add the butter bit by bit until emulsified. Alternatively, place into a blender, blitz, then transfer to a pan and heat until the mixture reaches 70°C. Return to the blender and blitz again, adding the butter bit by bit until emulsified

Season the sauce with salt and lemon juice, then pass through a sieve and allow to cool

For the mushroom noisette, add all the ingredients to a pan and heat until the butter browns and becomes beurre noisette. Pass through a fine sieve and reserve both the mushrooms and the beurre noisette

When ready to serve, reheat the monkfish by steaming it at 43°C and then cooking it in foaming butter until caramelised. Alternatively, cook in foaming butter from chilled until heated all the way through. Unwrap and slice the monkfish into 10g portions and season with salt. Gently reheat the fermented celeriac sauce then froth with a hand blender

In the bottom of each bowl, place a spoonful of the mushrooms from the beurre noisette. Place a piece of monkfish in the centre of the bowl, then spoon the fermented celeriac sauce around it. Drizzle over the mushroom beurre noisette and serve