Unagi no Oshizushi

Ingredients

• 1eelready-grilled fillet, cut to fit the mould or into strips about 1 cm wide
• 14⅛ ozsushi ricefold in the vinegar mixture while still warm
• 3 tbspVinegarready-made or mixed from rice vinegar, sugar and salt
• 1½ tbspsugarfor the sushi vinegar, plus a pinch for the omelette
• 1 tspsaltfor the sushi vinegar, plus a pinch for the omelette
• 1Eggfried as a thin omelette and cut into fine strips
• 3myoga gingerhalved lengthways, thinly sliced and briefly simmered (optional)
• 1 tbspsakefor briefly simmering the myoga
• 1 tbspsoy saucefor simmering the myoga, also the base of the eel sauce
• 1 tbspmirinfor simmering the myoga and for the eel sauce
• 1 tbspunagi saucedrizzled over before serving; reduced from soy sauce, mirin, sake and sugar
• spring onionfinely chopped, as topping (optional)
• 1 tspgingergrated, to taste (optional)
• ½ tspsesame seedsroasted, for sprinkling (optional)

Method

1. Cook the sushi rice and, while it is still warm, fold through the sushi vinegar (or rice vinegar, sugar and salt) until the grains glisten, then let it cool to room temperature.
2. Trim the grilled eel to the length of your mould, or cut it into strips about 1 cm wide.
3. Beat the egg with a pinch each of sugar and salt, fry it in a pan as a thin omelette, let it cool and cut it into fine strips.
4. Halve the myoga lengthways, slice it thinly and bring it briefly to the boil with the sake, soy sauce and mirin; drain and squeeze out gently.
5. Line the oshibako — or a rectangular storage container — with cling film or baking paper so the rice does not stick.
6. Add a layer of rice and press it flat, spread the myoga over it, add another layer of rice and lay the eel, egg strips and fine spring onion sprouts on top.
7. Fold the film over the topping, set the lid in place and press down firmly and evenly.
8. Lift the block out of the mould by the film and cut it into bite-sized pieces with a sharp, dampened knife.
9. Drizzle with the eel sauce just before serving.

Tips and variations

The order can be reversed: lay the eel skin-side up in the bottom of the mould, fill only rice over it and turn the block out to serve; equally, you can use rice as the base and add eel and egg as the top layer. Instead of eel, raw fish and other toppings work well — prawns, scallops, tuna, salmon, avocado, daikon, tobiko — and tamagoyaki can stand in for the thin omelette; for the salmon version, top the fish with a reduced teriyaki glaze and a spicy mayonnaise sauce and blowtorch it briefly at the end. You can also make the eel sauce yourself: simmer soy sauce, mirin, sake and sugar for about 20 minutes and thicken with a little slaked starch. To serve, arrange the cut pieces offset into a chequerboard pattern and offer grated ginger, roasted sesame seeds or — in place of the eel sauce — wasabi and soy sauce alongside.