Heat oil in a pan.
Add onion and fry till its color turn to golden brown.
Now mix together yogurt, coriander powder, chili powder, nutmeg, mace, turmeric, saffron, ginger garlic paste and salt.
Add this to the pan and fry well.
Now add trotters and continue to fry.
Add stock, cover and cook over low flame for 30 minutes.
Turn the flame off.
Add all spice powder, green cardamom and black cumin seeds.
Serve with coriander leaves, green chilies, lemon, mint leaves and ginger juliennes.