In a large pot, heat 2 tablespoons of olive oil over medium heat for about 2 minutes until shimmering. Add 1 finely chopped onion and sauté for 3-4 minutes until it becomes translucent. Stir in 3 minced garlic cloves and cook for another minute.

Once the garlic is fragrant, introduce 2 diced carrots and 2 chopped celery stalks to the pot. Stir them in for about 4-5 minutes. Next, incorporate 1 cubed zucchini and 1 diced bell pepper, cooking for an additional 3 minutes.

Pour in 4 cups of vegetable broth, bring the mixture to a gentle boil, then reduce the heat to low, adding 1 teaspoon each of dried thyme and rosemary, along with 1 bay leaf. Simmer uncovered for 15-20 minutes until the vegetables are tender.

Season your soup with freshly cracked black pepper to taste, remove the bay leaf, and stir in chopped fresh parsley right before serving. Top with Parmesan cheese if desired.