In a large pot, heat the olive oil over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and cook for an additional 1-2 minutes until fragrant.
Add the chopped cabbage and sliced carrots to the pot, stirring to combine. Cook for about 5 minutes until the cabbage begins to wilt.
Pour in the vegetable broth and water. Add the dried thyme, salt, and black pepper. Bring the mixture to a boil.
Reduce the heat to low and let the soup simmer for 20-25 minutes, or until the vegetables are tender.
Stir in the diced tomatoes and apple cider vinegar. Simmer for another 5 minutes.
Taste and adjust seasoning if necessary. Serve hot, garnished with fresh parsley.