Heat the water and broth in a pot. When it starts to boil, add the pasta and cook it. Half of the time indicated on the package (we will finish cooking it in the sauce). Remove it from the pot and save all the cooking liquid.
We clean the chicken, removing possible traces of fat and cut it into cubes of approximately one centimeter. Heat the oil in a frying pan and fry until lightly brown. We remove and reserve.
Cut the leek into thin slices. We sauté it in the same pan (we may have to add a little more oil) until be tender. Add the cream cheese, the grated old Amsterdam cheese, four ladles of the cooking liquid, the liquid cream, salt and black pepper. Cook for a couple of minutes, counting from the moment it starts to boil.
We crush the sauce and pass it through a strainer to make it very thin (optional). Return the sauce to the pan, add the pasta and cook until al dente.
We plate the pasta with the chicken cubes on the surface (although we can also add them to the sauce) and the grana padano cheese in chips. Garnish with some chopped fresh chives and serve immediately.