1 Put the oil, onions and bay leaves into a pan and slowly cook until softened.
2 Add the ras al hanout, harissa and tomato purée and continue to cook for another minute or two.
3 Add the sugar and vinegar, bring to a bubble, add the salt, pepper and stock, then bring to a simmer and cook gently for five minutes to reduce a little. (You can do this ahead of time, then warm the mixture up when you need it.)
4 Preheat the oven to 185 degrees
5 Brush a casserole dish with a little olive oil.
6 Season the fish, then lay them in the casserole, skin side up.
7 Spoon the onion mixture over the gurnard and bake it for 12-15 minutes, depending on the thickness of the fish.
8 Serve with some basmati rice and a scattering of pine nuts and parsley.