Place the onion in a food processor, fitted with the grater attachment. Shred and move to paper towels and press out all the excess liquid. Transfer to a bowl. Repeat the process with the potatoes and add them to the onion.

Add the eggs, salt, pepper, and flour, and mix everything until well combined.

Preheat oven to 300 degrees. Line a large baking sheet with a double layer of paper towels.

Pour a solid layer of oil in the bottom of a large nonstick pan over medium-high heat. When the oil is hot enough, working in batches, spoon rounded 1/2 tablespoons of the mixture into the pan (make sure they don’t touch each other.) Flatten slightly with the back of a spoon—they should be about 1 1/2 inches in diameter.

Fry until golden brown, about 2 minutes on the first side and 2 minutes on the second side. (If they start to burn, adjust your cooking time and/or change out your oil for a clean amount.)

Transfer the latkes to the lined baking sheet to drain and place in the oven so that they stay warm until all are cooked.

Garnish with smoked salmon, sour cream, and dill. Serve warm.