Place the Potato (3), Tomato (2), Onion (2), Carrot (2), and Celery (2 stick) into a large saucepan and add the Canned Tomatoes (1 can), Garlic (1 clove), Bay Leaf (2), Dried Oregano (1/2 teaspoon),and Fresh Parsley (10 gram).
Pour in Water (1.2 liter) and Olive Oil (1 tablespoon) and cook on high heat until the soup starts to boil. Cover the pan with a lid and turn the heat down to medium or medium-low. Simmer the soup for about 30 minutes until the vegetables are tender, stirring frequently.
Lightly mash the vegetables with a potato masher to help thicken the soup. Be careful not to overdo it though as you still want the soup to be chunky.
Season the soup with Ground Black Pepper (1 pinch) and Salt (1 teaspoon) and cook for another 5 minutes.
Sprinkle the rest of the Fresh Parsley (5 gram) over the soup and serve warm.