In a pan heat some olive oil, add: celery, onion and carrot. Fry until the onion becomes translucent.
Now add the garlic, give it a stir and fry for a few more minutes.
Now add two thirds of the beans and the potato. Cover the vegetables with cold water, put the lid on and start to simmer for the next hour or so, until the beans become soft.
Now add the tomatoes and cook for 20 minutes.
Blend everything into the consistency of a cream.
Add the rest of the beans, sage leaves, the rosemary , salt and pepper. In a separate pan brown the bacon strips and add them to the soup.
Cook the soup on a gentle heat with the lid on. Stir occasionally, the soups of a creamy consistency tend to stick to the bottom of a pan very quickly.
The soup is ready when the beans are soft. Adjust the seasoning and remove the herbs.
Boil the pasta in salted water until al dente ( according the timing on the package ).
Pour the soup into serving bowls, arrange the pasta on the top and drizzle with olive oil.