I would like to cook the Mughlai Chicken - can I omit the golden sultanas? Would it alter the flavour drastically?
Nigella's Mughlai Chicken (from FEAST) is a rich and aromatic chicken curry made with cream, yogurt and almonds. Golden sultanas are added to provide a little sweetness and these are sometimes sold labelled as golden raisins. If you can't find golden sultanas then you could use regular dried sultanas or raisins instead, though not currants as they are quite small and slightly less sweet.
If you can't find either of these alternatives, or if you don't like dried fruits, then you can omit them from the dish. The flavour won't be exactly the same but it is still a very delicious curry without them.