Heat the oil in a large wok or frying pan over a medium heat. Add the onion, chilli and curry leaves, and stir-fry for 4–5 minutes. Add 4 tablespoons of the measured water and continue to stir-fry for a further 2–3 minutes.
Add the garlic, ginger, ground coriander, curry powder and chicken, and stir-fry over a high heat for 10 minutes. Add the remaining measured water and the peas, and continue to cook for 6–8 minutes until the chicken is cooked through.
Remove from the heat and stir in the lemon juice and herbs. Season to taste, and serve immediately with warmed chapatis and natural yogurt.