Peel the potatoes and remove any dry skin from the onion. Put them in water to keep them from browning.

Using a box grater, grate the potatoes and onions (alternate them because the onion will keep the potatoes from browning) Grate half of the potatoes on the medium holes and half on the small holes.

Grate the onion on the small holes and add to the potatoes.

Strain the potatoes and onions in a mesh strainer over a bowl.

When most of the liquid is strained off, give the mix a squeeze to get the rest of it out.

Mix the potatoes and onions with the egg, flour, salt and baking soda. Add back some of the potato water if it’s too stiff.

Heat a skillet over medium heat, and then add enough oil to generously cover the bottom of the skillet.

When the oil is hot (350 degrees if you have a thermometer) spoon the mix into the hot oil and spread it out into a pancake. Be sure to them spread out thin so they cook through in the middle. Don’t plan on doing all of them in one batch, you don’t want to overcrowd the pan.

Fry until the bottom is brown; you should be able to see the bottom edges.

Flip them with a spatula and a fork (this helps to hold the Deruny in place and let you gently set it down in the oil so it doesn’t splash) to finish the other side.

Serve with sour cream, and garnish with dill.