Season Parmigiano Reggiano cheese croutons in a pan with oil and shallot. Add cream and water (or vegetable stock) in equal parts and boil until the sauce is reduced by 1/3. When lukewarm, add grated Parmigiano Reggiano cheese to obtain the sauce. Blanch asparagus tips and cool in cold water. Cook pasta in salted boiling water, drain and dress using asparagus tips seasoned in a pan with oil and salt. Pour the Parmigiano Reggiano cheese sauce in the dish, place Fagottini and finish with sliced black truffle.