Heat the vegetable oil in a large pot over medium heat. Add the minced garlic and chopped onion, and sauté until the onion is translucent and garlic is fragrant, about 2-3 minutes.
Add the beef or vegetable broth to the pot. Bring to a boil, then add the diced potatoes, bay leaf, and dried marjoram. Reduce heat and simmer until the potatoes are tender, about 10-15 minutes.
Season the soup with salt and pepper to taste. Remove the bay leaf.
While the soup is simmering, heat a small amount of oil in a skillet over medium heat. Add the bread cubes and toast until golden brown and crispy.
Ladle the soup into bowls and top with the toasted bread cubes. If desired, sprinkle with grated Parmesan cheese and garnish with fresh parsley.
Enjoy your meal!