Cover the potatoes with water and place in a large saucepan. Bring to a boil. Reduce heat to low and simmer for 20-30 minutes. Drain the mixture, then mash it and season with salt and pepper. Let the mixture cool before you begin to make the filling.
In a large frying pan, heat 1 tablespoon oil and cook the onions for 5 minutes. Season the mixture with the garlic, mushrooms and lemon juice. Cook the mixture for 15 minutes, or until the mushrooms are softened and most of the liquid is evaporated. Remove from the heat and add the chopped dill.
Start shaping the dough by mixing the flour with the mashed potatoes. Flatten a few tablespoons of the dough into patties. Place about a tablespoon of mushroom mixture in the center. Top with more potato mixture. Form into potato cakes.
In a large frying pan, heat some oil. Once the oil has gotten hot, add the potato cakes to the pan and cook each side for approximately 2 minutes until they are golden brown.
Enjoy!