Boil pasta in some salted water .
As the pasta is cooking, saute onion and garlic in some olive oil then add rapini and a 1/2 cup of the boiling pasta water, salt and pepper and cook until tender (approx. 5 minutes)
Add cooked pasta to the pan, stir in the ricotta cheese and toss until well mixed.
Drizzle with a little extra virgin olive oil and sprinkle with some fresh grated parmigiano reggiano and serve.