Drain one can of cannellini beans, reserving the liquid. Blend the beans with this liquid until smooth and set aside.

In a large pot, heat 2 tablespoons of olive oil over medium heat. Add the chopped onion and sauté for 4-5 minutes until translucent. Stir in the minced garlic and cook for 40 seconds.

Incorporate the pureed bean mixture into the pot, along with the other two drained cans of cannellini beans, the canned tomatoes, chili flakes, dried basil, dried rosemary, and bay leaf. Pour in the vegetable broth and stir well.

Increase the heat and bring the mixture to a gentle simmer. Cover and cook for 25-30 minutes, stirring occasionally.

Remove from heat, stir in the chopped parsley or basil, and adjust seasoning with salt and pepper. Serve hot with olive oil and bread.