Bring lots of water to a boil. Add salt to it, add in broccoli and cook for 2 mins. Drain it and set aside.
In the same pot add pasta and cook till done.
When the pasta is cooking, make pesto. take cashews, garlic, red chilli flakes, salt, parmesan cheese and pulse few times till it is blended. Add in broccoli and olive oil and pulse few times so it is coarsely crushed.
Now drain the cooked pasta and add it to a bowl, add in this pesto and toss well. Add little pasta cooking water if needed.