Chicken Tikka Masala (#1)

Chicken Tikka Masala originated from the kitchens of Bangladeshi chefs in Britain. It is probably the most popular Indian dish in the world. Indeed, British politician Robin Cook described it as "a true British national dish". Its popularity has proven so great that almost every Indian restaurant worldwide now offers it. It has conquered even the Indian subcontinent, and has arguably replaced Tandoori Chicken as the flagship of Indian food.

Being a lover of Chicken Tikka Masala, I have found myself on a endless quest for the "perfect recipe". With that in mind I have begun to collect recipes. This is a decent base line recipe that I enjoy at home.

Additionally, if you have a recipe for Chicken Tikka Masala that you think I should try, and include in my cookbook. Please take a moment and submit your recipe to me using my Recipe Submission Form, I promise I will try your recipe!
Thanks!

675 g (1.5 lb) cooked Chicken Tikka
2 tbs olive oil (see Notes, tips and variations below)
4 large cloves of garlic, finely chopped
200 g (7 oz) onions, finely chopped (optional)
1 tin (can) of plum tomatoes, chopped
1-4 chopped fresh green chillis (depending on strength of the Chillis and the desired strength of the sauce)
2 tbs chopped fresh cilantro (coriander leaves)
50 mL (4 fl oz) single cream
1 tbs malt vinegar
2 tbs curry paste
2 tbs tandoori paste
1 tbs tomato paste
1 tbs garam masala

1. Heat the oil in a wok (if available, otherwise a large frying pan).
2. Add the garlic and onions (if using) and stir-fry until browned.
3. Add the curry and tandoori pastes and mix well, adding a little water.
4. Add the cooked chicken tikka and stir-fry for two minutes to heat through.
5. Add the tomatoes, vinegar, tomato paste and chillies and simmer for five minutes. Add more water if required.
6. Add the cream, garam masala and chopped cilantro and simmer for a few minutes.
7. Garnish with fresh coriander and serve with Naan bread, Saffron Rice With Pine Nuts , onion bahjis and/or a good glass of white wine.

Notes:
Mustard seed oil is preferable to olive oil if you can find it.
Powdered or dried ingredients can be substituted for fresh, but at the expense of taste.