Heat the olive oil or butter in a large pot over medium heat. Add the diced onions and cook for about 5 minutes until they become translucent. Add the minced garlic and sauté for an additional minute until fragrant.

Add the sliced mushrooms to the pot, stirring occasionally. Let them cook for about 8–10 minutes until they release their moisture and begin to brown.

Add the diced potatoes to the pot, then pour in the broth. Stir everything together and bring the mixture to a boil. Once boiling, reduce the heat to a simmer and cover the pot. Let it cook for about 15–20 minutes until the potatoes are tender.

For a creamy soup, use an immersion blender to blend the soup until smooth, or transfer it in batches to a regular blender. If you prefer a chunky texture, blend only half of the soup or skip this step entirely.

If you want a richer texture, stir in the milk or heavy cream at this stage. Let the soup simmer for another 5 minutes, stirring occasionally.

Taste the soup and season with salt and pepper to your liking. Ladle it into bowls and garnish with fresh parsley or chives.