In a large pan, add all the ingredients for making the stock and let it come to a boil.
Cook the meat until tender, it will take one hour to one and half hour.

Remove the meat from the stock and keep aside.
Strain the stock to remove the whole spices. Keep the stock aside to use later.

In a large pan, add the butter. When the butter is hot, add the chopped onion, bell pepper and fry until light brown.

Add the ginger paste, garlic paste to the onion and fry for a minute on medium heat.

Add the cooked meat and all the spices, fry for three minutes on medium-low heat.
Beat the yogurt and add to the meat, stir, and cook until the oil separates and comes to surface.

Pour three cups from the meat stock and cook until the oil separates again.
Add the mustard seeds and stir for a few seconds.
Taste the curry, add more salt if required. If it tastes sour because of the yogurt, cover and cook for 1 minute on medium-low heat.

Serve with rice or chapati dough.