Dry roast the cumin seeds, fennel and coriander together and then grind with the drained chillies.
Mix the ground spices with ginger, lemon juice and salt in a bowl.
Chop chicken into bite size pieces.
Add chicken into the bowl and mix with half the marinade thoroughly.
Cover and refrigerate overnight. Keep the rest of the marinade in the fridge as well.
Heat oil in a steep sided pan or wok. You¦ll need at least 1 inch of oil in bottom of pan.
Fry chicken pieces (covered in marinade) a few at a time, do not overcrowd. Chicken should take only a few minutes to cook and will be dark golden brown on outside, white and juicy on the inside.
Allow each batch to drain on kitchen paper and allow oil to re-heat before next batch.
You can keep chicken warm in a low oven until all is ready.