1Cut the chicken into bite-sized pieces and set aside.
Finely chop the onions, green chilies, and tomatoes.
Heat the vegetable oil in a large pan over medium heat.
Add the mustard seeds and let them splutter.
Add the chopped onions and sauté until golden brown.
Stir in the ginger-garlic paste and cook for 1-2 minutes.
Add the chopped green chilies and tomatoes, and cook until the tomatoes are soft.
Mix in the turmeric powder, red chili powder, and salt.
Add the chicken pieces and cook until they are browned on all sides.
Pour in the vinegar and a little water, then cover and simmer for 20-25 minutes until the chicken is cooked through.
Garnish with fresh coriander leaves before serving.