Soak the beans: Place dried cannellini beans in a large bowl, cover generously with cold water, and soak for at least 12 hours or overnight. Drain and rinse thoroughly.

Cook the bacon: In a large stockpot or Dutch oven over medium heat, cook chopped bacon until golden and crispy. Transfer to a paper towel-lined plate, leaving approximately 3 tablespoons of bacon fat in the pot.

Sauté the vegetables: Add diced onion and chopped carrots to the bacon fat. Cook for about 5 minutes until slightly softened. Stir in minced garlic and rosemary and cook for another minute.

Add the remaining ingredients: Pour in the chicken stock, add the drained beans, and stir in the tomato paste until combined.

Cook the soup: Bring to a full boil and boil for at least 30 minutes, adding hot stock or water as needed to keep the beans covered. Reduce heat, partially cover, and gently simmer until the beans are completely tender, usually another 30–60 minutes or longer.

Blend for creaminess: Remove from heat. Carefully use an immersion blender to blend part of the soup until creamy, leaving some whole beans for texture.

Season: Add salt and freshly ground black pepper to taste. Adjust consistency with extra stock if needed.

Serve: Ladle into bowls, top with reserved crispy bacon, and garnish with additional fresh rosemary if desired. Serve warm with crusty bread.