Wash, peel and grate the potatoes and onion. For a finer pancake like those pictured, finely grate the potato and onion, but for a crunchier pancake, go for larger-sized grated potato and onion pieces. Transfer to a mixing bowl.
In a separate dish, crack an egg and whisk until combined, then add it to the mixing bowl with the potato and onion. Add the salt and pepper and combine.
To the same mixing bowl, gradually add the flour and combine well. The batter should be thick, chunky and wet but not runny. Add a little more flour if necessary, then let the batter rest for 15 minutes.
While the batter is resting, finely chop the fresh dill, spring onions/scallions and/or chives, pour some sour cream or crème fraiche into a dish, and lay paper kitchen towels onto a wire rack or tray for draining the pancakes after they're fried, as you’ll want to serve the pancakes immediately once they’re done.
Heat a medium-sized fry pan or skillet to medium-high heat and add enough cooking oil to cover the bottom of the pan. Drop a little mixture in the pan; if it sizzles it’s ready.
Turn down to medium heat then drop a tablespoon of batter into the pan, using a spatula to quickly flatten it and shape it into a circle before it sets and the edges starts to brown.
Repeat until you’ve filled the pan. You should be able to cook 4 or 5 pancakes in one batch. By the time you finish shaping the fourth or fifth pancake, the first pancake should be ready to turn over. Each batch should take around 5 minutes to cook.
Using a turner or spatula, flip the first pancake over. If it’s not brown yet, then leave the others for another minute or so, then turn one over. If it’s nice and brown and crispy, then turn the others over one by one, and flip the first one over again so it’s brown and crispy on both sides.
As they're done, transfer the pancakes to the wire rack to soak excess oil, then repeat until you’ve used up all the batter. If you're not serving the pancakes immediately transfer them to a tray in a warm oven.
Serve immediately while still crispy with extra salt and pepper, and dishes of fresh dill, spring onions/scallions and/or chives, and sour cream. If you don’t serve the pancakes straight away they will start to soften.