Put the fish cakes in a large, wide pan and pour over just enough water to cover (about 500ml). Set aside to soften for 2 mins.

Remove the fish cakes from the pan using tongs or a slotted spoon and set aside, keeping the water in the pan. Add the rice cakes, spring onions and onion to the pan along with the tteokbokki sauce ingredients and a little black pepper. Cook over a medium heat for about 20 mins, stirring occasionally until the rice cakes have softened and the sauce has thickened, topping up with a little extra water if it becomes too dry.

Meanwhile, make the béchamel. Melt the butter in a saucepan over a low heat. Whisk in the flour until incorporated, then gradually pour in the milk, whisking continuously until fully incorporated. Cook for 6-8 mins until thickened. Season well.

Heat the grill to medium. Spoon some of the tteokbokki sauce into a medium baking dish, then layer over some of the perilla leaves, grated cheese and a layer of the fish cakes. Repeat until you have used all the ingredients, reserving a little of the cheese for the top. Pour over the béchamel and sprinkle over the reserved cheese.

Cook under the hot grill for 10-15 mins until the top is deep golden and bubbling. Sprinkle over some extra perilla leaves to serve.