Step 1: Prepare the Vegetables

1. Wash and chop all the vegetables. Dice the onion, mince the garlic, slice the carrots and celery, and chop the cabbage into bite-sized pieces. If using a potato, peel and dice it into small cubes.

Step 2: Sauté the Aromatics

1. Heat the olive oil or butter in a large soup pot or Dutch oven over medium heat.
2. Add the diced onion and cook for 3-4 minutes, stirring occasionally, until it becomes translucent.
3. Add the minced garlic and cook for an additional 1-2 minutes, stirring frequently, until fragrant.

Step 3: Add the Vegetables

1. Stir in the sliced carrots, celery, and potato (if using). Cook for 5 minutes, stirring occasionally, until the vegetables begin to soften.

Step 4: Add the Cabbage and Tomatoes

1. Add the chopped cabbage to the pot and stir to combine with the other vegetables. Cook for 2-3 minutes to allow the cabbage to start wilting.
2. Pour in the can of diced tomatoes (with their juices) and stir well.

Step 5: Add the Broth and Seasonings

1. Pour in the vegetable broth (or chicken broth) and stir to combine.
2. Add the dried thyme, oregano, bay leaf, smoked paprika (if using), black pepper, and a pinch of salt. Stir to distribute the seasonings evenly.

Step 6: Simmer the Soup

1. Bring the soup to a gentle boil over medium-high heat, then reduce the heat to low. Cover the pot with a lid and let the soup simmer for 25-30 minutes, or until the vegetables are tender.
2. Stir occasionally and taste the broth halfway through cooking, adjusting the seasoning with more salt or pepper if needed.

Step 7: Add Optional Add-Ins

1. If adding cooked rice, quinoa, barley, beans, or meat, stir them into the soup during the last 5 minutes of cooking to warm through.

Step 8: Serve and Enjoy

1. Remove the bay leaf from the soup before serving.
2. Ladle the hot soup into bowls and garnish with fresh parsley, grated Parmesan cheese, or crushed red pepper flakes, if desired. Serve with crusty bread or crackers for a complete meal.