In a large, lidded frying pan gently cook 1 finely chopped medium onion, 4 crushed garlic cloves, 40g peeled and grated root ginger, 2 thinly sliced medium red or green chillies, 2 tsp ground cumin, 1 tsp cumin seeds, 1½ tsp ground turmeric, 1 tsp each black mustard seeds and fenugreek seeds and 8-10 curry leaves in 1 tbsp ghee over a low heat with the lid on for about 5-6 minutes, stirring occasionally until the onions have softened.
Add ½ tbsp tomato purée and 500ml vegetable or mushroom stock, season then bring to the boil and simmer gently for 15 minutes or until the sauce has reduced by two thirds.
Cut 250-300g oyster, shiitake or chestnut mushrooms evenly in half or into quarters then add to the sauce. Season and continue to simmer gently for 10 minutes or until the sauce is just coating the mushrooms. (It might seem a bit dry to start with as the mushrooms will absorb the sauce initially then release the liquid as they start to cook.)
Meanwhile, heat a drizzle of vegetable or corn oil in a non-stick frying pan over a medium-high heat. Cook 4 parathas for about 2-3 minutes on each side until crisp, golden and puffed up. Transfer to warmed serving plates.
Stir 2 tbsp roughly chopped coriander leaves into the mushrooms, check for seasoning then spoon them on to the parathas.
