In a pot of boiling salted water cook your pasta el dente reserving at least 2 cups before draining
While the pasta is cooking, in a large saute pan over medium heat add the olive oil, then add in the onion and garlic and cook until soft and fragrant , but not brown.
Add the peas and cook 4-5 minutes until the peas are cooked but not mushy. Then add in the pasta water and the ricotta. Simmer until sauce thickens (3-5 minutes ).
Add the parmesan cheese , and freshy ground black pepper, salt according to taste,
Plate top with more parmesan and the freshly chopped Italian parsley.