Prepare the spice blend by mixing the curry powder, turmeric, cumin, ground coriander seeds and cinnamon in a small bowl.Heat the oil in a large skillet. Add the onion and saute for 4 minutes over medium heat..Add the diced apple and cook for another 2 minutes.Add the minced ginger and garlic and stir.Add the spice blend to the onion mixture and stir constantly as it cooks for 2 more minutes.Add the flour and stir constantly as it cooks for 2 minutes. Scrape the bottom of the pan to prevent burning.Gradually add the chicken stock, stirring constantly to prevent lumps from forming.Add worcestershire sauce, sugar, tomato puree and stir. Season with salt and pepper.Bring the sauce to boiling point, stirring constantly. Then reduce the heat to low and simmer the sauce for 15 minutes.Turn the heat off, and allow the sauce to cool slightly before blending. When cool enough add the sauce to a blender or food processor and blitz until smooth.Return the sauce to the pan over medium heat. Add golden raisins if desired.Serve hot with a side of chips or french fries.