Start by chopping the cabbage into small bite-sized pieces. Set it aside.
In a large pot, heat a small amount of oil over medium heat.
Add the chopped onion and garlic, sauté for about 5 minutes, until the onion becomes translucent.
Add the sliced carrots, celery, and bell pepper into the pot. Cook for another 5 minutes, stirring occasionally.
Stir in the cabbage, diced tomatoes, vegetable broth, oregano, basil, salt, and black pepper. Bring the mixture to a boil.
Once boiling, reduce the heat and let the soup simmer for about 25 minutes, or until the vegetables are tender.
After the soup has finished simmering, add the lemon juice to brighten the flavors. Adjust seasoning as necessary.
Serve hot, garnished with fresh herbs if desired.