1. Grind coconut .
2. Chop the coriander leaves ,ginger and green chillies .
3. Mix all the spices and coconut together with salt .
4 . Add 2 tbsp oil and mix well .
5. Peel potatoes ,sweet potatoes and yam .
6. Slit vegetables and into four .
7. Stuff with prepared masala .
8. Bind together .
9. Heat 3/4 cup oil in a pan .
10 . Add the vegetables
11. Stir well ,Cook over extremely slow fire for 1 1/2 hours , keeping a little water on the lid of the pan to prevent burning .
12. The vegetables and spices should be well cooked .
13 . Test for salt and remove .