Start by clarifying the butter. Melt the butter in a heavy pan over a low heat, then use a spoon to skim off the foam as it rises to the surface. Carefully pour the yellow liquid underneath into a bowl, leaving any milky solids in the pan.

Put the grated potatoes into a clean dish cloth, then twist and squeeze until the excess liquid is removed. Tip into a bowl, add the flour, sage and eggs, then season with salt and pepper and mix.

Preheat the oven to 180°C Fan/Gas Mark 4.

Heat a quarter of the clarified butter in a cast iron frying pan over low- medium heat and when it’s hot, add a quarter of the rosti mix. Pat the mixture down with a flat spatula, then cook for 3 minutes without moving it. When you have a nice golden colour underneath, carefully turn the rosti over using the spatula and repeat on the other side. Once a good golden-brown colour, the rosti should be cooked. Transfer to a large ovenproof plate and repeat with the remaining mixture and clarified butter.

When all the rostis are cooked, place them in the oven to warm while you fry the eggs to your liking. In the restaurant we cook them sunny side up, so heat a little sunflower oil in the frying pan, crack the eggs into it and cook for 3 minutes, or until the white is completely set.

Place 1 warm rosti on each of 4 plates, then top each one with a fried egg and 3 anchovies. Finish with a grinding of black pepper.

Prepare the batter just before you want to coat your ingredients. In a clean, dry bowl, whisk the egg whites with a hand-held electric mixer (beater) until they form soft peaks. Put the flour and oil into a large bowl, then slowly whisk in the sparkling (seltzer) water with a balloon whisk until it reaches a double (heavy) cream consistency, then fold in the egg whites just before coating your ingredients. The batter will keep in the fridge for 5 hours but not with egg whites. So if you don’t want to use it straight away, don’t add the whites and just add them before using it.

Put the trout fillets into a pan with the stock, then bring to a simmer and cook for about 9 minutes, or until the fish is cooked through and the flesh flakes.

Meanwhile, heat the oil in a deep fryer or deep, heavy pan to 180°C, or until a cube of bread browns in 30 seconds.

When the trout is nearly cooked, cut the courgettes into matchsticks to resemble thin fries (think McDonald’s). Put the sticks into a bowl and coat with the batter.

Working in batches, carefully lower the sticks into the hot oil one at a time and deep-fry for about 3 minutes until golden (after 2 minutes, use a pair of tongs to move the fritti around so they don’t stick together). Remove with a slotted spoon and drain on a plate lined with paper towels. Repeat with the remaining courgette sticks, then sprinkle with salt.

Remove and discard the skin from the trout fillets, then place on 2 plates, add a tablespoon of lemon mayonnaise or aioli to each and serve with the courgette fritti on the side.

To make the custard, pour the milk and cream into a pan, then add the vanilla bean and seeds and heat to just before boiling. Meanwhile, fill a large bowl with ice and set another heatproof bowl or container on top. Put the egg yolks and sugar into a heatproof bowl and whisk together until combined. Slowly pour a large ladleful of the warm mixture over the egg yolks and sugar, whisking constantly so it does not curdle, then return the mixture to the pan and cook over a medium-low heat, stirring slowly with a rubber spatula, until it reaches 83°C on a sugar thermometer. Remove from the heat, then immediately pass through a chinois sieve into the bowl set over the ice bath and leave to cool. When cool, cover and place in the fridge until you need to use it. Keep in an airtight container in the fridge for up to 3 days.

Line the bottom and sides of a 900g loaf pan with baking paper, then lay the bun halves on top of each other in the pan.

In a bowl, beat together the eggs, milk, sugar and cream, then pour over the bread so everything is submerged. Cover with cling film and place in the fridge overnight.

The next day, preheat the oven to 180°C Fan/Gas Mark 4. Remove the cling film and bake the pudding for 45 minutes, then leave to cool. When cool, cover with another piece of baking paper and cut a piece of cardboard to put on top of the pudding in the pan. Add something heavy on top, like a food can, to press the pudding and chill in the fridge overnight.

The next day, turn the pudding out onto a clean work counter and cut into 5 thick slices. Put enough sugar into a shallow bowl for coating the slices after they have been deep-fried.

Heat the oil in a deep fryer or deep, heavy pan to 180°C, or until a cube of bread browns in 30 seconds. Carefully lower 2 slices of pudding at a time into the hot oil and deep-fry for 4 minutes on each side, or until golden brown on the outside and warm on the inside. Remove with a fish slice and drain on a plate lined with paper towels for a few seconds, then coat the slices in sugar on all sides.

To serve, pour the cold custard into 5 serving bowls, then top with the warm bread and butter pudding.

Put the citrus peel, rosemary, cinnamon stick and sugar into a pan, cover with water and bring just to the boil. Reduce the heat and simmer for 12 minutes to let the flavours infuse. Add the pears and simmer for 20-30 minutes until soft but still holding their shape.

Just before serving, make the chocolate sauce. Put the cocoa powder, sugar and 110ml of water into a pan and bring to a simmer, whisking constantly until combined. Remove the pan from the heat, then whisk in the butter until incorporated and the sauce is glossy.

To serve, cut across the bottom of each pear to create a flat edge so they can stand upright. Divide the warm chocolate sauce between 2 plates, then place the pears on top and serve immediately.