Wash lion's mane mushrooms and pull them apart into bite sized chunks. Add all ingredients for the marinade and mix well. Marinate for about 1 hour - overnight for deeper flavour.
Add 1 tbsp oil and roast all the masala ingredients (except coconut, garlic, and ginger) for 2–3 mins till fragrant.
Add in ginger-garlic paste and saute for a minute.
Add grated coconut, roast until the mixture is browned. Cool and grind with splash of water to a smooth paste.
Heat oil in a wider and heavy-bottomed pan. Add onions and sauté till golden brown. Add tomatoes and cook till soft and oil starts to separate.
A secret hack that my family taught me is to slice the tomatoes and cook them face down - then mash them directly in the pan so you get all the juices in.
Add powdered spices - garam masala, kashmiri chili powder & turmeric.
Add the ground masala paste and cook the paste with onion-tomato mixture for 10-15 minutes on medium flame till oil releases. This is really a patience game! It might cook faster or take slightly longer depending on the heat and the nature of the pan.
While this is cooking, air fry the lion's mane mushroom at 180C for about 10-12 minutes with a drizzle of oil.
Add curry leaves to the gravy and give it a good mix.
Add the fried lion's mane mushroom and mix well with the masala. Add salt, black pepper and a splash of water if too thick.
Cover and cook on medium heat for about 20 minutes, stirring occasionally. Add more water for a gravy-style curry or reduce it for a dry roast style.
Garnish with fresh coriander. Serve hot with steamed rice, chapathi, dosai or idiyappam. Enjoy!