This is a mughlai dish. The gelletinous meat and the marrow helps to build up the calcium level in aging people,builds strength in sick and pregnant, and also curbs pains in joints.
It’s a good match with Hoppers,stringhoppers, iddli,dosai,and pulaos.Trotters can be used for making soup too.To cook this you need a pressure cooker.I will not recommend the use of normal pans,because the meat around must be tender,and the marrow should be almost out of the bone.(adding to the flavour).Now for the Recipe

Ingredients
2 sets of cleaned trotters/paya
1 onion chopped
1 tblsp.   ginger-garlic paste
2 green chillies
1 tsp.chilli powder
1 tsp.Coriander powder
1/2 tsp turmeric powder
3/4 tsp.cummin powder
3 cloves
3 cardamons
1 piece cinnamon
2 star anise
1/4 tsp mustard seeds
1/4 tsp saunf
6-7 peppercorns
Sea moss -small piece(optional)
Few curry leaves
1/4 cup grated coconut
1 tblsp.rice flour
2-3 tblsp.lime juice
2 tblsp.oil
Salt to taste

Method
Before you start cooking,wash the trotters 2 times and immerse in water with a pinch of turmeric for 20 minutes.
Grind the cardamons,coconut,rice flour and set aside.
Using the non sharp side of the knife,scrape away the black part lightly from the bones.(not the meat please).
Heat a pressure cooker, Add the oil, and when it is hot add the mustard seeds,the spices, next onions and saute till onion is translucent. Add green chillies, ginger-garlic paste and now the trotters.Cook for further 1-2 minutes. Add water above the level of the trotters,and cook for 20 whistles. (do not add salt and spice powders now).
After 20 whistles, allow the steam to release on its own.
Open the lid,add the rest of the ingredients except lime juice and cook for a further 5 more whistles.
Remove from fire. After the steam is off remove,and add lime juice.
Note:You could adjust the gravy to your need,by adding water or coconut milk. .

Note:For paya or trotters soup
It’s just the omission of chilli powder and coconut paste.