Creamy asparagus and pea pasta

Remove asparagus tips and set aside.
Bring stock to the boil. Toss in the peas and asparagus and return to the boil.
Cook for about five minutes, depending on the thickness of the asparagus.
Place the asparagus tips in a sieve over the boiling water and cover with a lid. The tips will steam while the other parts are cooking.
Purée cooked peas and asparagus with the stock until smooth.
Add crème fraiche, seasoning and basil and purée to blend well. Return to the pot, add asparagus tips and gently heat through.
Meanwhile, cook pasta in lots of salted, boiling water until al dente. Drain pasta and toss with sauce.
Serve with freshly grated Parmesan cheese and black pepper.