Leek and potato soup with smoked haddock and potato doughnuts

Start by poaching the smoked haddock, as the leftover milk can then be used in the soup. Place the haddock portions in a small pan and cover with the milk. Place over a medium heat and gently bring to the boil, then take off the heat and leave the fish to cool in the milk. Carefully remove the fish and reserve until ready to serve. Remember to reserve the milk

To make the crispy potato garnish, preheat an oven to 180ºC/gas mark 4. Slice the potatoes very finely on a mandoline, then use a small round cutter to stamp out 24 circles (you can use the leftover potato trimmings for the soup, just make sure they're grated or finely chopped). Toss with the clarified butter, then lay out 12 circles on a baking tray lined with baking paper and top each one with a second circle. Cover with a sheet of greaseproof and another tray and bake until crisp and golden, about 8-10 minutes. Sprinkle with salt and once cooled, store in an airtight container until ready to serve

To make the soup, place a large pan over a medium heat with the butter. Once it has mostly melted, add the sliced onion and cook for a few minutes until translucent. Then add the grated potato, garlic, curry powder, thyme and yeast. Cook for a further 8–10 minutes, stirring regularly

Add the leeks and cook for a further 5–8 minutes. Once they are soft, remove 4 teaspoons of the leeks and set aside for garnish. Pour in the wine and reduce by half. Add the water and reserved poaching milk and cook for 4 more minutes

Finally add the cream, parsley and/or spinach and cook for a couple more minutes, then transfer to a blender. Blitz for a good few minutes until smooth and velvety, season with salt and lemon juice, then pass through a fine sieve. Chill down as quickly as possible if not serving straight away, to preserve the bright green colour

To make the parsley garnish, heat a pan of oil to around 160ºC. Carefully add the leaves – they may spit a little so stand back. Once crisp and slightly translucent, remove from the oil and drain on kitchen paper. Keep the oil hot for cooking the doughnuts later

To make the doughnuts, place the water, butter, sugar and salt into a pan and bring to the boil. Once the butter has completely melted, add in the flour and stir vigorously on a high heat until it forms a ball that comes away from the sides of the pan. Continue cooking for a few more minutes, stirring constantly to make sure the flour is cooked out

Place the mix in the bowl of a stand mixer with a paddle attachment and mix at a slow speed, adding the eggs one by one. Once the eggs are mixed in increase the speed until the mixture is fully combined into a smooth dough

Whilst the dough is still warm, weigh it and then weigh out the same amount of warm mashed potato. Place both back into the food mixer and mix until you have a smooth dough

Roll the dough out into small walnut-sized balls (about 7g each). Ensure your pan of oil is at 180ºC and, in batches, deep-fry the doughnuts for 2 minutes, flipping with a spoon halfway if needed to get a nice even golden brown. Drain on kitchen paper

To serve, gently reheat the soup and the haddock in the oven for a few minutes until hot. Spoon the reserved cooked leeks into the bottom of each serving bowl and place the haddock on top. Finish garnishing with the crispy potato and parsley leaf. Serve the potato doughnuts on the side and carefully pour the soup into bowls at the table