1. For the latkes, put the grated potato and onion into some kitchen paper or a tea towel and squeeze out the excess moisture.
2. Put the potato and onion in a bowl and mix in the beaten egg, salt and pepper, and then mix in the flour. Put a frying pan over a medium heat and add the oil.
3. With about a tablespoon of the potato mixture, form a small patty and place it into the pan and repeat until the mixture is used up and cook until golden brown, then turn the latkes over and brown the other side; you may have to do a few batches. Drain on kitchen paper.
4. For the horseradish cream, mix together the crème fraiche, horseradish and lemon juice and season to taste. To serve, spoon the horseradish cream onto the latkes, top with smoked salmon and dill to garnish. You may want to serve it with some lemon wedges as well.