Preheat the oven to 190°C fan or Gas Mark 6. Scrub the potatoes with a wet kitchen paper and prick each one with a fork. While they are still damp, sprinkle lightly all over with sea salt flakes. 

Put the potatoes on a baking sheet – not touching – and scatter the sheet with a little water by shaking wet hands over it. Bake for 1 – 1 ½ hours; this varies according to the size of the potatoes. To test them: they should feel soft under the skin and ‘give’ a little.

While the potatoes are cooking, roughly chop the beetroot and toss with the shallot, dill and a little seasoning. 

When the potatoes are ready, split them open, season and put some butter on both halves. Fill with the beetroot mixture and the salmon, squeeze lemon juice on top, then add a dollop of crème fraiche and spoon on some caviar. Grind some pepper and serve with the bitter leaves.