Dry roast red chilies, coriander seeds, cloves, cinnamon, cardamom, peppercorns, cumin and mustard seeds till fragrant and slightly browned.
Blend in a blender along with ginger, garlic, vinegar and tamarind paste to make a smooth paste.
Add little water while making the paste.
Heat oil in pan.
When the oil is hot, add chopped onion and fry till golden brown.
Add chicken and fry on high heat for 3- 4 minutes.
Add tomato puree and the paste that we made.
Now add salt, turmeric powder and 1 cup of water and cover and cook for 45-50 minutes.
Add sugar and cook for another minute.
Serve hot with steamed rice or Chapati.
You can increase or decrease the spice level according to your heat preference.I have used Kashmiri Red chillies which gives this curry a fiery red colour but they are not as spicy.Roast the spices on medium low heat for best flavour.You can replace the chicken with pork, beef or eggs.