Heat the olive oil in a large pot over medium heat.
Add the chopped onion and minced garlic. Sauté until the onion is translucent, about 5 minutes.
Add the sliced carrots and celery to the pot. Cook for an additional 5 minutes, stirring occasionally.
Pour in the vegetable or chicken broth and add the diced potatoes.
Bring to a boil, then reduce heat and simmer for 10 minutes.
Stir in the green beans, bay leaf, dried thyme, and dried marjoram.
Season with salt and black pepper to taste.
Simmer for another 10-15 minutes, or until the vegetables are tender.
If using, stir in the diced ham or bacon and cook for an additional 5 minutes.
Remove the bay leaf.
Ladle the soup into bowls and garnish with fresh chopped parsley.
Enjoy your meal!