Boil the potatoes with bay leaf until fully cooked.
While the potatoes are cooking, heat one tablespoon of oil in a large pan.
Dice the onion and coarsely chop mushrooms.
Add the onion and mushrooms to the pan and cook on medium-low heat mixing occasionally until all the liquid evaporated. This will take about 15-20 minutes.
Cook for another 5 minutes until the mixture starts to brown.
Season to taste with salt and pepper. I use 1/4 teaspoon each salt, pepper, and dry thyme.
Finally chop the dill (or other herbs you are using), add it to the pan with the mushrooms, mix and take off the heat.
Once the potatoes are cooked, drain them well and mash with fork or masher, do not use food processor as it'll turn the potatoes watery. Season to taste.
Cool the potatoes.
Add flour to the mashed potatoes and mix well.Alternatively, you could use leftover mashed potatoes.
Take about 2 tablespoons of potato dough and flatten into a disk, place one spoonful of mushroom filling and cover with a bit more potato dough. Form into a disk.
Once all the potato cakes are assembled, heat the remaining tablespoon of oil in a large pan.
Place potato cakes on the pan and fry about 5 minutes until they turn golden, flip and fry another 5 minutes until golden. IMPORTANT: Use more oil if needed.
Serve with the leftover mushroom mixture if any left, some lemon juice, mustard or horseradish.
You can omit flour or add less than the recipe calls for. I like flour as it makes the potatoes easier to handle, but it certainly isn't necessary.Filling can vary. You can add different herbs like thyme, for example, or parsley. Or add bell peppers.You will most likely have a tiny little bit of the mushroom filling leftover, just serve it alongside the potato cakes.I have a really good non-stick pan (affiliate link) so the cakes don't stick too much, but if you are worried, add more oil to make sure that they don't stick. I know some readers had trouble with the frying part. Note, that quite often food will stick to the pan until it's actually done and only once it's properly cooked, it'll get released. In any case, please add oil as needed when frying the cakes. Also, they can be baked instead of fried.