Marinate the chicken in oil, salt, turmeric, minced ginger, and garlic. Set it aside for about 20- 30 minutes or overnight in a refrigerator.
Make the masala
Add oil to a pan kept over medium heat. Add the spices (red chilies, cumin seeds, mustard seeds, black peppercorns, cinnamon stick and cloves) along with garlic and stir fry till the spices turn fragrant (takes about a minute)
Grind the spices along with coarsely chopped tomatoes and 1/4 cup vinegar to make a fine paste.
Instant Pot Instructions
Add oil in the steel insert of an Instant Pot and press the 'Saute function'. Set the selection to 'Normal' heat. When the oil heats up, add onions and fry them till they are soft and translucent (about 5-6 minutes).
Add salt and marinated chicken and mix well. Let the chicken cook for about 2-3 minutes.
Add the ground masala and mix well. Add 1/2 cup water.
Press the “Warm / Cancel” button and then select “Pressure Cook.” Adjust the time to 5 minutes and set the pressure selection at high. Cover the Instant Pot lid and lock it. Make sure the vent is at sealing position.
Once the cooking cycle is complete, move the vent to the venting position to release pressure. Carefully open the lid and give a good stir.
Add sugar (if using) and mix well. Do a taste test - add more vinegar/salt if needed.
Serve hot with pav or rice/roti or naan.
Stovetop Instructions
Add oil in a wok/kadhai kept over medium heat. When the oil heats up, add onions and fry them till they are soft and translucent (about 5-6 minutes).
Add salt and marinated chicken and mix well. Let the chicken cook for about 2-3 minutes.
Add the ground masala and mix well. Add 1/2 cup water and mix well.
Cover and cook the chicken for about 15-20 minutes while stirring occasionally. Cook till you can easily cut the chicken pieces into two using a fork/spoon.
Remove the lid and add sugar (if using) and mix well. Do a taste test - add more vinegar/salt if needed.
Serve hot with pav or rice/roti or naan.
Notes
Variations + Tips / Tricks
You can marinate the chicken in the masala that you have created in step 2. You can set it aside in the refrigerator for 30 minutes or overnight.
The authentic recipe calls for palm vinegar - if you don't have that handy substitute it for rice or cider vinegar and a tablespoon of sugar (or jaggery).
Also, although the recipe calls for 1/2 cup of vinegar, use only 1/4 at first. Add the remaining 1/4 cup after the chicken is cooked - one tablespoon at the time, followed by a taste test. This prevents the dish from becoming super tangy.
You can skip the tomatoes and replace it with fresh tamarind. Take tamarind (the size of a ping pong ball) and soak it in hot water for about 15 minutes. Run it through a sieve. Add the juice along with vinegar in the blender for making the base masala.
Add 1/4 cup coconut milk to give it a creamy touch. Add this in the blender for making the base masala.