Heat the butter and oil in a large heavy-based saucepan. Add the flour and stir for 3 minutes or until lightly browned.
Stirring continuously, add the cardamom, fennel, masala, garlic, ginger and onion.
Sauté for 3 minutes, ensuring there are no lumps. Stir in the stock, tomato paste and saffron and cook until slightly thickened.
Season with salt and pepper, add the seafood and cook for a further 5 minutes. Add the cream if being used and stir through.
Serve immediately garnished with coriander.