Add your pasta and just enough broth or water to cover the pasta.
As for any risotto, you add successive ladlefuls of liquid as the prior ones evaporate, until the pasta is cooked al dente. By the end, most but not all of the cooking liquid should have evaporated.
Add grated cheese, mix well and serve immediately.
Notes
This recipe is best made with small soup pastas like orzo (aka risoni).