Heat oil in a heavy-bottomed vessel and add a few curry leaves along with the chopped onions. Sauté until the onions turn soft and translucent.
Once the onions are ready, add 1 tablespoon of crushed ginger and garlic (using a mortar and pestle helps release the full aroma). Sauté well until the raw smell of the ginger and garlic disappears.
Stir in the East Indian Bottle Masala or red chilli powder and fry it for a minute to release its deep, spicy flavors.
Add the chicken pieces and mix well, making sure each piece is coated with the masala.
Pour in about 1 cup of water. Cover and cook on medium heat for 10 to 12 minutes until the chicken is tender.
Now, add a sliced tomato, along with blanched carrots and potatoes. (Blanching the vegetables beforehand helps them cook faster and evenly.)
Adjust the consistency of the gravy by adding water, if needed. Cover and cook for another 5 minutes on medium heat.
In a small bowl, make a slurry with rice flour and water (1 tsp rice flour + 2–3 tbsp water) and stir it into the curry. This helps to slightly thicken the gravy.
Finally, add lemon juice or vinegar for a touch of tang, sprinkle some garam masala, and garnish with fresh coriander leaves.
Serve with rice or rotis