Step 1: Heat the olive oil in a large Dutch oven or stockpot over medium heat. Add the diced onion, carrots, and celery. Sauté for 7-10 minutes, stirring occasionally, until the vegetables begin to soften.
Step 2: Stir in the minced garlic and tomato paste. Cook for an additional 1-2 minutes until fragrant, being careful not to burn the garlic. This step builds the foundational flavors for the BEST Cabbage Soup.
Step 3: Add the shredded cabbage, diced potatoes, and diced red bell pepper to the pot. Stir well to combine all the vegetables with the aromatics.
Step 4: Pour in the vegetable broth and the undrained can of diced tomatoes. Add the dried oregano, dried thyme, and bay leaf. Bring the mixture to a boil.
Step 5: Once boiling, reduce the heat to a simmer, cover the pot, and cook for 20-25 minutes, or until all the vegetables, especially the potatoes and cabbage, are tender. The longer it simmers, the more the flavors of this BEST Cabbage Soup will deepen.
Step 6: Remove the bay leaf from the soup. Taste and season generously with salt and freshly ground black pepper. If desired, stir in a pinch of red pepper flakes for heat or a squeeze of fresh lemon juice to brighten the flavors.
Step 7: Ladle the hot soup into bowls. Garnish with fresh chopped parsley or cilantro before serving. This BEST Cabbage Soup is delicious immediately and tastes even better the next day.