Pierogi Fillings - mushrooms, cabbage and mushrooms, potato and cheese

For Christmas I usually make 3 different fillings, mushrooms and cabbage and mushrooms are traditional filling at Christmas time. My son only likes the potato and cheese filling so I make this most common in Poland pierogi filling as well.

Mushroom filling
Ingredients:
1 cup of dried wild mushrooms, soak (water from soaking can be added to the cabbage stew, cabbage and mushroom filling, or barszcz)
2 cups of mixed mushrooms. Usually I opt for mushrooms like oysters, shittake, chanterelles, or any mushroom available locally
1 large onion
sea salt, pepper to taste

Steps:
Sauté finely chopped onion for a few minutes
Add finely chopped mushrooms (both soaked dried and fresh) to the pot
season with salt and pepper
Usually there is no need to add any water as salt will pull water from mushrooms so you will have enough juice for cooking.
Cook on a very low heat for several hours (gas mark 1.6-2.2 for 4-6 hours), stirring occasionally (once every 30 min or so).


Cabbage and mushrooms filling
Ingredients:
0.5 cup of sauerkraut (drained)
0.75 cup of fresh cabbage
1 large onion
1 cup of mushrooms (dry and fresh)
0.25 tsp caraway seeds
salt and pepper to taste
2 prunes (might be needed if your sauerkraut is very sour)

Steps:
Sauté finely chopped onion for a few minutes
Add finely chopped sauerkraut, fresh cabbage, and mushrooms
Add the spices - caraway seeds, salt, and pepper
Cook on a very low heat for several hours (gas mark 1.6-2.2 for 4-6 hours), stirring occasionally (once every 30 minutes or so).


Potato and cheese filling
Ingredients:
500 g of cooked potatoes (soft like for mashed potatoes)
500 g of quark or pressed cottage cheese (you can make your own with milk and yoghurt)
1 onion
1 tbsp ground cumin
salt, pepper to taste

Steps:
Sauté finely chopped onion for a few minute
Mash potatoes with cheese
Mix all ingredients together