Peel and chop the onions and garlic cloves finely, shred or chop the cabbage roughly (avoid fine shredding as you want the texture of wider pieces), grate the carrot if using, and peel and cut potatoes into cubes.
In a large fry pan, skillet or Dutch oven, fry the finely chopped onion in a neutral cooking oil until soft, then add the finely chopped garlic cloves, and continue frying until the onion is translucent, taking care not to burn the garlic. Transfer to a large soup pot.
Fry the roughly shredded cabbage with bay leaves in neutral cooking oil until soft. If using carrot, add this now also. When soft, transfer to the soup pot.
Add the potatoes and 2 litres of water to the soup pot, along with the tomato paste, turmeric, salt, pepper, sugar, and extra virgin olive oil, and stir. Turn to high heat to bring to a boil, then turn down to medium to allow to simmer for an hour. Add another litre of water; feel free to add more if needed.
At around 30 minutes, add the rest of the water, taste the soup, season with additional salt and pepper if needed.
When the soup is done to your liking (feel free to simmer for more than an hour if you like; the longer the broth simmers the better it tastes), add the chopped fresh dill and curly-leaf parsley and combine well so that it doesn’t clump together.
Ladle out the cabbage soup into bowls and (if you’re not vegan) plop a dollop of sour cream into each bowl and sprinkle on more dill and parsley. Provide additional bowls of sour cream and dill on the table for guests to help themselves.