My family is fairly spice adverse. (We love in a party of the US where some say ketchup is spicy - haha!) I didn't have the 100 grams Chicken Tikka Sauce, so I put in 2 Tbsp Mild Curry, and 2 tsp Roasted Red Chili Paste. Instead of the cream, I put in 7 oz. Unsweetened Coconut Milk (from a can). Instead of Coriander stalks, I used flat-leaf parsley stalks. It tastes good, but could be spicier in my opinion.
