1) Coarsley grate the potatoes and onion into a large bowl, or use a food processor with a coarse grating blade.
2) Leave the mixture to rest for about 15 mins so the liquid releases from the onions and potatoes.
3) Carefully drain off the liquid for about 30 mins until the mixture is dry, then put in a cheese cloth and squeeze out the remaining liquid.
4) Add the eggs, flour, 1 tsp sea salt and pepper, and mix well.
5) Pour the oil into the pan so that it is 2-3cm deep. Set over a medium heat for a few minutes until it ripples.
6) Carefully spoon in the mixture to the size you want – 2 tbsp for large latkes or 1 tbsp for small.
7) Fry them in batches to avoid overcrowding the pan, and cook on each side until browned for 2 mins.
8) Remove to a plate lined with kitchen paper, then season with a sprinkling of salt.
9) Serve with the soured cream and smoked salmon, finished with a sprinkling of chives, or just apple sauce – both are traditional.