Rinse and drain the rice well then place the rice and stock in a large pan. Bring up to a simmer then cover and cook over a low heat for 10 minutes. Switch off the heat (do not remove the lid) and leave to sit for 10 more minutes.
Meanwhile, place the parsley, coriander, mint or basil, dill, garlic, lemon juice, cumin, salt and olive oil in a blender, ideally a high powered one with a tamper tool.
Blend until smooth, stopping to scrape down the sides as needed.
Slice the spring onions thinly and roughly chop the pistachios.
Mix the herb paste into the cooked rice along with the chopped pistachios, spring onions, rocket and a good grinding of black pepper. Serve ideally right away.