In a large pot heat the olive oil on medium high heat. Once hot add in the bacon and saute for 5 minutes until crisp and then add in the onion, garlic and diced celery and saute for 3 minutes until the onion begins to soften.

Add in the tomato paste and rosemary and stir before adding 4 cups of chicken stock and 2 cups of cannellini beans. Bring to a boil and then reduce the heat to medium and leave to simmer for 20 minutes (if the liquid begins to evaporate too much, add another cup of chicken stock).

While the beans are cooking place the additional 1 cup of cannellini beans in a tall container with a splash of water and blend until smooth using an immersion blender.

After 20 minutes add in the additional 2 cups of chicken stock and 1 cup of ditali pasta plus the pureed cannellini bean paste and bring to a boil. Leave the pasta to boil for 10 minutes or until al dente. If there is not enough liquid in the pot, add a splash more, it should be a thick stew like consistency.

Remove the pot from the heat and leave to sit for 2 minutes before sprinkling with parmesan and serving.