MAKING THE SAUCE

Heat oil in a large frying pan, and add 2 chopped onions on a medium heat. Cook for 2 minutes, then add 2 tbsp ginger & garlic paste and stir.

Cook the ginger and garlic paste with the onions until the raw smell disappears. Add ½ pint of water, salt, and bring to the boil - allow to boil for 20 minutes.

Once boiled for 20 minutes, remove from the heat, allow to cool and blend in a food blender until completely smooth. (You could alternatively use an immersion blender if you have one - be careful not to burn yourself, the mixture will be very hot.)

Once the mixture has been blended to smooth, clean the pan, and heat 1 tbsp vegetable oil in it.

Add 1 tsp turmeric, 1 tsp cumin, 1 tsp paprika, 1 tsp chilli powder and 1 tbsp tomato puree to the hot oil, stir and mix.

Add tomato passata (or blended chopped tomatoes) to the hot oil spice mixture, and stir thoroughly. Bring to a low simmer and cook for a further 10 minutes, then turn the heat off.

Add the onion mixture to the tomato mixture and mix - this is the curry sauce base. Set aside whilst you stir fry the chicken and vegetables.

STIR FRYING

Heat 2 tbsp oil in a frying pan on low/medium heat, and stir fry the remaining 2 chopped onions for 15 minutes until sweet and clear.

Add 1 tbsp of garlic & ginger paste to the pan, stir and cook for 30 seconds, until it begins to brown.

Then add the tsp each of curry powder, coriander and turmeric, and 2 tbsp sugar - stir fry for 10 seconds then add the diced chicken pieces and fry on high until the chicken gets some color (2-3minutes).

Add peppers, and any chills you'd like - fry for a further 2 minutes.

Turn the heat down slightly and add the prepared curry sauce - cook for a further 10 minutes, until the chicken has cooked through.

Remove from the heat once the chicken has cooked through, and top with fresh coriander. Serve with rice and naan bread for a true restaurant classic.