Instructions:

1. Peel and finely chop the onion.
   
2. Peel and slice the carrot into rounds.
   
3. Heat a drizzle of oil in a pot and sauté the onion and carrot over medium heat, stirring often, for a few minutes.
   
4. Meanwhile, peel and cut the potatoes into sticks or cubes. Add the potatoes to the pot and continue cooking the vegetables, stirring frequently.
   
5. Clean and slice the mushrooms. Add the mushrooms to the pot and cook, stirring often, for about 10 minutes.
   
6. Pour 1 liter of water into the pot, add a couple of bay leaves, a bit of salt, and a few whole black peppercorns. Cover, bring to a boil, and simmer until all the ingredients are cooked (20-30 minutes).
   
7. Serve garnished with a sprinkle of chopped parsley.