Drain the potatoes and dry on kitchen paper. Heat the vegetable oil in a deep pan over a medium heat until hot (or heat a deep-fat fryer to 180C/350F). CAUTION: hot oil can be dangerous. Do not leave unattended. Deep-fry the potatoes in batches until crisp and golden-brown. Remove from the oil using a slotted spoon and drain on a plate lined with kitchen paper. Season with salt.
For the curry, heat the oil in a heavy-based pan or karahi over a medium heat. Add the whole spices and fry for a minute until fragrant, then add the onion and fry for 10 minutes, or until softened and golden-brown.
Stir in the tomatoes and salt and simmer for 2â€“3 minutes, then add the ginger, garlic, chilli powder, cumin, coriander, garam masala and turmeric and cook for a minute.
Add the chicken pieces to the pan and cook, stirring, for 2â€“3 minutes, or until well coated with the spice mixture, then add the jaggery, apricots, vinegar and enough water just to cover. Bring to the boil, lower the heat, cover the pan with a lid and simmer for 30â€“40 minutes, or until the chicken is cooked through and tender, and the sauce is reduced to a rich, thick consistency.
Serve with the potato sticks heaped on top, and scatter with coriander.