Mix the Jalfrezi spice blend with 2 Tbs of the cooking oil into a paste.
Smear this over the chicken pieces and leave to marinate for two hours in a fridge.
Put the onions and the garlic, finely chopped, in a pan with Tbs oil and fry until soft and light brown. Stir in 2 Tbs Jalfrezi mix and fry for 1 min.
stirring continuously. Add tomatoes and cook on high heat for 2 mins.
Add juice of lemon, 1 tsp ground black pepper and liquidise to a thick sauce. Simmer.
Fry the chicken pieces in the remainder of the cooking oil until lightly browned. Put into sauce and simmer for 10 mins, adding a little water if necessary. Add salt and chillipowder (optional) to taste
Garnish with the coriander leaves and serve with boiled rice or naan bread.