Wash and chop the onions, carrots, mushrooms, and potatoes into bite-sized pieces.
In a large pot, heat the olive oil over medium heat. Add the onions and sauté until they become translucent. Follow with the carrots, cooking for 2-3 minutes or until they start to soften.
Add the chicken pieces to the pot (or beef if you're using it) and sear until they turn a golden brown color.
Stir in the mushrooms and cook for a minute before adding the potatoes. Mix well to combine the flavors.
Pour in the stock followed by the buckwheat, stirring well to combine all the ingredients.
Add salt, black pepper, and bay leaves to the pot, adjusting the seasoning according to your taste.
Cover the pot and allow the soup to simmer on medium heat for 10-15 minutes, letting the flavors meld.
Once the soup is ready, serve it in bowls, garnished with a sprinkle of fresh parsley. For a creamy touch, stir in a tablespoon of yogurt in the center of the bowl before serving.