In a large pot, heat olive oil over medium heat. Add the sausage and cook until browned, breaking it up with a spoon, about 5 minutes.

Remove the sausage from the pot and set aside, leaving the drippings in the pot.

In the same pot, add onion, celery, carrot, and garlic. Sauté until the vegetables are softened, about 5-7 minutes.

Add the cannellini beans, chicken broth, thyme, rosemary, and the cooked sausage back into the pot. Bring to a boil.

Reduce heat and simmer for 15 minutes.

Using an immersion blender, blend the soup until smooth, or transfer to a blender in batches and blend until smooth.

Return the blended soup to the pot.

Stir in the heavy cream and season with salt and pepper to taste. Heat through for another 5 minutes.

Serve hot, garnished with fresh herbs if desired.