Wash the Chicken. Take the boneless chicken thighs and wash them in cold water. Put them into a colander and pat dry with a kitchen cloth. Add the 50g of garlic and ginger paste to the bowl, along with half a teaspoon of salt. Using your hands to mix everything together in the colander, to make sure the chicken gets a really even coating of the mix. Put 65ml of natural yoghurt into a new bowl. Add half a tablespoon of oil and half a tablespoon of chilli powder. Whisk these ingredients together. Cover the chicken with the whisked mixture. Once again use your hands to make sure that the chicken is thoroughly coated in the mixture. Add a tablespoon of vegetable oil and keep mixing. Cover the chicken in cling film and put it in a refrigerator. Leave the chicken to marinate for no less than 4 hours. After 4 hours, put the pieces of chicken on some greaseproof paper, and place under the grill for 10 to 15 minutes. There is no need to turn them. Remove the chicken from the grill and leave to cool for a few minutes. Then cut it into bite-sized pieces. Cover with cling film or plastic wrap and put it back in the refrigerator. Start by peeling and finely chopping 15g of ginger. Then heat 40ml of vegetable oil in a large saucepan, on a medium to high heat. When the oil is hot, add the four sticks of cinnamon to the pan. Then, add the 5 cardamom pods. 5 cloves. and a few bay leaves. stir for a couple of minutes, then add the chopped ginger, cook for a further minute and add the 6 green chillies. Put the 750 g of fresh, whole tomatoes into the pan and stir. Turn the hob down to a medium heat and carry on stirring for a couple of minutes. Turn the heat down low and leave to sit for about a minute. Then add 100ml of water, put the lid on, and leave to simmer for about 25 minutes until the tomatoes are cooked to a puree. Take the pan off the heat. Remove any whole spices. Now you need to crush the tomato mixture into a paste like consistency. You could use a wooden spoon, but a blender is preferable. Blend until smooth. Use a sieve to strain the pureed mixture into the saucepan to get rid of any lumps. Add a little water to get all the mixture out. Put the pan on a high heat to bring it back to the boil. In the meantime, use the blender to grind about two thirds of the cashew nuts, that's 50g, into powder. Then add a tiny amount of water and blend into a paste. Once the sauce is hot and bubbling, add one tablespoon of tomato paste. Then the ground cashew nuts. Add a little water to the blender to get all the paste out. Add half a teaspoon of chilli powder. and a tablespoon of honey. and stir for about 3 minutes. Then add 50g of butter and stir until it melts. Next, a generous sprinkling of salt. Leave the sauce for about 5 minutes and then stir in one teaspoon of Kasoori methi, which are the ground dried fenugreek leaves. Leave the sauce gently bubbling over a medium heat and move onto stage. Finish the sauce. In another frying pan melt a little butter. Use a sharp knife to roughly chop the remaining third, or 25 g, of the cashew nuts and add them to the pan. Then, throw in the seasoned chicken tikka that you grilled earlier. Fry for about 3 minutes on a high flame. Add the sauce. Cover the chicken with the sauce. Then add 60 ml of single cream. Then stir the chicken and sauce together for about 3 minutes. It should be simmering while you do this. Serve. Decorate with a little drizzle of cream and serve with naan bread or rice.