Put the coconut into a bowl and cover with 2 cups of boiling water; stir, and let sit for 20 minutes.
Meanwhile heat the oil in a large saucepan, then put in the onion; cover, and let cook over gentle heat for 7 minutes.
While the onion is cooking, halve the chilies, remove the seeds, then slice the chilies finely and add to the saucepan, along with the garlic (Keep your hands away from your face while preparing the chilies, and wash them well afterwards because the juice can burn your skin).
Add the spices to the saucepan, stir well, and cook for a further 1 to 2 minutes.
Strain the coconut liquid, discarding the solids.
If you have a food processor or blender, whizz the cashews to a smooth, creamy consistency with the coconut liquid; or, grind the cashews as finely as you can (an electric coffee grinder does this well, in small batches), then mix with the coconut liquid.
Either way, add this mixture to the saucepan; season with salt and pepper, cover, and remove from the heat.
Cook the broccoli and green beans in a large covered saucepan containing 1/2 inch of boiling water, to half-boil, half-steam them, until they are only just tender.
Keep them well on the crisp side as they will cook a bit more when they are added to the korma.
Drain the vegetables, then stir them gently into the creamy cashew mixture, along with the frozen peas.
Cook over gentle heat until the korma is hot.
Check the seasoning, sprinkle with the cilantro, and serve.