Finely chop half the red onion and save the other half for the garnish.
Mince the garlic, and dice the red chilli. Roughly crush the cashew nuts with the side of your knife. Chop the paneer into large dices of about 2cm.
Peel, and finely grate the ginger. Pick the leaves off the coriander, and finely chop the stalks.
The remaining half of the red onion should be sliced as thinly as possible, then left to soak in ice cold water.
Over a medium high heat, melt the butter, and fry off the red onion with the salt.
When the onion is translucent, add the garlic and chilli, cooking them out for about one minute.
Add all the dried spices, and toast them until fragrant.
Fry off the ginger and coriander stalks until any juices evaporate. Add the crushed tomatoes, paneer and crushed cashew, and leave to simmer until the gravy has thickened.
Adjust the seasoning to taste. Add the frozen peas, and heat them through before serving.
Peel, halve and finely slice the shallots. Pick the coriander leaves.
Mix together the flours and mustard seeds, then whisk in about 400ml water, enough to make a thin batter. Heat a large frying pan to medium hot, add a splash of oil and wipe it around with kitchen paper. Add a small ladleful of batter to the pan and swirl it immediately to get it as thin as possible. When the top looks dry, heap on a couple of large spoonfuls of the matar paneer, then roll up the pancake - it should be brown and crispy underneath. Transfer to a plate and garnish with sliced shallots and coriander.
«This batter keeps well in the fridge. You could replace the matar paneer with sag aloo, or any other relatively dry curry.»