Baked Mackerel with Rhubarb

Method

• To make Tuna Fish Cakes, start by draining the canned tuna. 
• While the rice is cooking, prepare the eel by grilling or frying it.
• Put the tomato paste, olives, and butter into a blender or food processor and whizz until smooth.
• Put the oats in the blender or food processor, slightly broken up.
• Coat the fillets with the butter mixture while grilling.
• Heat a large skillet over medium-high heat and add the fish cakes.
• Lay two sheets of baking parchment on the counter and season the fish with salt, pepper and the chopped rosemary.
• Dip in the flour and coat each fishcake. Dip in the egg and then coat with crumbs. Repeat this process until you have 24 fishcakes. Chill the fish cakes for one hour.
• Drizzle some olive oil over the fish, then slide the mackerel into the oven.
• Roast the mackerel for around 10 minutes, until they're a nice golden colour and there's no pink in the middle of the fish (check by slicing into it).
• Remove the fish from the oven and take it out of the parchment, setting it aside to rest before serving.
• Add all the ingredients for the sauce – capers, sherry vinegar, chopped rosemary, and a good glug of olive oil – to a small saucepan and warm through for 3 mins until piping hot.
• Take the mackerel fillets off and lay them on a serving plate along with the roasted rhubarb.
• Serving Suggestions: Sprinkle the sauce with a little chopped fresh parsley over the mackerel and serve!