Heat the oven to 180C/160C fan/gas 4. Wrap the baking potato tightly in foil and bake for 1 hr 15 mins, or for 40-50 mins at 160C in an air-fryer until tender when pierced with a knife (or microwave, without foil, for 8-10 mins). Leave to cool slightly, then halve and scoop the flesh out into a large bowl. Mash slightly. (Try our loaded potato skins recipe)

Melt the 50g butter in a small frying pan over a low heat and continue to cook until it has browned and smells nutty. Leave to cool.

Put the coarsely grated potato in a clean tea towel and squeeze out the excess liquid. Mix the grated potato into the mash, then sift in the flour, bicarb, 1/4 tsp salt and the white pepper. Stir to combine, then stir in the browned butter, egg and buttermilk to make a batter. Mix in the parsley and chives.

Heat the 2 tbsp butter and rapeseed oil in a frying pan over a medium heat until foaming. Reduce the heat to medium-low and spoon in tablespoons of the boxty mixture, frying for 3 mins on each side until just turned pale golden (you’ll need to do this in batches). Remove to a plate and cool.

Top each with the soured cream and large flakes of smoked trout, then garnish with the dill fronds and a pinch of sliced chives.