For the potato goulash, cut the potatoes into coarse pieces. Finely dice the onions, dice the remaining vegetables as well.
Squeeze the garlic, slowly roast the onions in a saucepan over low heat until light brown (about 20 minutes), add the tomato paste.
Then add the garlic and the vegetables. Add paprika powder, caraway seeds, marjoram, lovage, deglaze with vegetable soup or water.
The potatoes should be just covered with water. Season with vinegar and salt and simmer for about 10 minutes. Then simmer slowly over low heat until the potatoes are cooked through and the goulash has a nice binding.
Simmer for about 30-40 minutes, depending on the size of the potato pieces, add water if necessary, season with salt and pepper to taste.
Add a piece of butter and serve the potato goulash with a tablespoon of sour cream and parsley per plate.