In a large pot, heat the olive oil over medium heat. Add the chopped onion, garlic, carrots, and celery. Sauté for about 5-7 minutes until the vegetables are softened.

Add Tomato Base

Stir in the tomato paste and diced tomatoes, cooking for an additional 2-3 minutes until fragrant.

Simmer the Broth

Pour in the vegetable broth, add the bay leaf, thyme, salt, and black pepper. Bring the mixture to a boil, then reduce the heat and let it simmer for 15 minutes.

Add the Fish

Cut the fish fillets into bite-sized pieces and gently add them to the pot. Simmer for another 10 minutes, or until the fish is cooked through and flakes easily with a fork.

Finish and Serve

Remove the bay leaf, stir in the fresh parsley, and adjust seasoning to taste. Serve hot.