Grate the potatoes and squeeze out excess moisture using a clean kitchen towel.

In a bowl, mix grated potatoes with chopped onion, beaten eggs, salt, and pepper.

Heat olive oil in a skillet over medium heat; shape the mixture into patties and fry until golden brown (about 5 minutes per side).

Layer cooked rostis with slices of smoked salmon to build your stack.

In a separate bowl, mix sour cream with dill and lemon juice; drizzle over the assembled stack before serving.