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.
Serve immediately.
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.