Wash and chop the potatoes into inch-sized pieces. In a large soup pan, melt two tablespoons of butter and cook the potatoes until they are beginning to brown, about ten minutes.
Dice the onions and add them to the pot with the potatoes. Stir and cook until the onions are translucent, about five minutes.
When the potatoes are fork-tender, stir in the minced garlic. Sprinkle marjoram and salt over the potatoes, onions, and garlic, and mix well. Add the bay leaves. Pour in the broth and bring the soup to a boil.
Once the soup has reached a rolling boil, cover and reduce the heat to simmer. Cook for an additional twenty to forty minutes, or until the potatoes are cooked to your liking.
Optional: For a smooth garlic soup, you can blend all but one cup of the soup in batches in a food processor or blender.
When ready to serve, optionally top with a handful of gruyere or mozzarella cheese and croutons. Serve hot.