Method

You want the puree to be nice and smooth so you can make this first. Melt a knob of butter in a saucepan over a medium heat and add the celeriac, cooking it until the edges start to brown

Pour in the milk and cream until the celeriac is covered and bring the pan back to a simmer. At this point cover with a lid and cook until tender

When the celeriac is ready (about 15/20 minutes), strain through a sieve and make sure to collect the milk and cream as we'll possibly use it later

Blitz the celeriac in a food processor until smooth and then push the puree through a sieve into a clean bowl to remove any lumps and roughage. At this point, if the puree is too thick, add a few spoons of the milk and cream mixture the celeriac cooked in. It shouldn't be too thick but it shouldn't have too much liquid in it either. You can chill this and pop it in a fridge until required

Heat oven to 140C

The first step is to flavour the butter. To do this we need to melt the butter in a frying pan large enough for the fish fillets to fit snugly. Once melted, add the shallot, bay leaf, peppercorns, ginger and garlic. Do this over a medium heat for a minute or so. The butter will start to colour but don't burn it. Strain the butter through a sieve to remove the solids and pour the flavoured brown butter back into the frying pan

Gently place the halibut fillets into the butter and make sure any exposed fish is basted with the butter. You'll want to cook the fish for about 3-4 minutes over a medium heat before transferring to the oven. Cook for another 3-4 minutes (depending on the thickness of the fish) until the fish feels firm

While the fish is in the oven, warm through the puree and to serve, spoon some puree on a plate and place the halibut on top. Finally, drizzle some of the browned butter over the fish