In a large pot or pressure cooker, add the mutton pieces, salt, 1 tsp pepper, 1 onion sliced, 1 slit green chilli, a few curry leaves and 1 tsp ginger-garlic paste and cook them and keep it aside.
If using fresh coconut milk, extract the milk from grated coconut by blending with warm water and straining it to get thick and thin milk separately.
Heat coconut oil in a large pot or pressure cooker over medium heat.
In another pot, heat oil, add 1 slit green chilly, ginger, curry leaves and onions and sauté until the onions are translucent.
Add the carrot and potatoes and water. Cover and cook until the vegetables are well cooked. Mash few potato pieces using the back of the spoon.
Add the cooked mutton along with water, 1 tsp pepper and garam masala and combine well. Wait till the water evaporates.
Add thin coconut milk and cook for another 5 minutes.
Stir in the thick coconut milk and simmer for 5-10 minutes, allowing the flavours to meld. Do not boil the stew after adding the thick coconut milk. Boiling can cause the coconut milk to curdle or separate, which can alter the texture and appearance of the dish.
Add curry leaves and 1 tablespoon coconut oil for aroma.
Serve hot with rice, appam, idiyappam, or paratha.