Sauce

In a stainless steel mixing bowl combine chicken with all ingredients for marinade. Allow to marinate for 4 at least 4 hours and up to overnight. PRE-HEAT OVEN TO 425F and remove chicken from marinade and transfer to a baking tray lined with parchment paper. Bake chicken for 15 minutes flipping once halfway. Remove from oven and allow to rest until required. Melt butter in a large saucepan or medium sized pot on low-medium heat. Then add all dry spices and cook gently for 4-5 minutes without burning. Add garlic, ginger, onion and chili and cook for 5-6 minutes until they begin to colour slightly. Then add tomato paste and cook out for 1-2 minutes before adding tomatoes and cashews. Cook for 20 minutes stirring often, if it becomes to dry and water. Remove from heat and blend in an immersion blender and strain before returning it to a clean cooking vessel on low medium heat. Add in chicken and bring to a gentle simmer for 15-20 minutes. Adjust seasoning and serve.