Pour the rice into a seive or colander and rinse well with cold water - not 100% necessary but ecourages the rice not to stick to each other. Bring a large pan of salted water to the boil and add the rice, once the pan comes back to the boil turn down the heat so that you have a rolling boil and stir just once - now add a lid or cover with a plate, I find the best results come from letting some of the steam out so leave the plate/lid slightly ajar. Get the onion and chop very finely (a shallot will be a little more delicate but an onion will be fine). After 10 minutes you should have perfect individual rice - it may be 9 minutes or 12 but try to your taste. When done, pour the rice into the colander and rince with boiling water from the kettle. Place the peas in a microwavable dish and cook on full power for 3 minutes, shaking half way through. Chop the butter into small cubes and place in a serving dish, now add the rice and sprinkle the peas, onion and pepper - toss well so that the butter and ingredients coat the rice.