Soak the beans in cold water overnight. Peel onions and garlic and cut into fine cubes. Clean, peel and slice carrots, clean and dice celery. Wash the rosemary and shake dry. Heat 2 tablespoons of oil in a pot. Sauté onions, 1 sprig of rosemary and prepared vegetables for about 3 minutes while stirring. Drain the beans and add with the broth.
Bring to the boil and simmer in a closed pot at reduced heat for 1 1/2-2 hours. Heat 4 tablespoons of oil, heat garlic and the remaining rosemary for 2 minutes. Pour through a sieve and collect. Finely chop half of the bean soup with a hand blender and put it back into the pot. In the meantime, prepare tagliatelle in boiling salted water according to the instructions on the packet. Season soup with salt and pepper. Arrange in plates with noodles and flavoured oil
12 hours waiting time