First make the kataifi filling using a large, high sided frying pan. If you have a small frypan I’d recommend doing this in two lots, halve the butter and kataifi and cook separately to ensure that it is completely toasted. In a very large frying pan with high sides melt the butter on medium heat and add the kataifi pastry breaking it up as you add it in. Toast the kataifi pastry well all over. This will take around 10 minutes to toast the whole batch. This is very important to ensure that you get the requisite crunch. In a large bowl mix the pistachio paste, tahini and salt and then add in the kataifi.