Onigirazu with omelette and cucumber

Step 1: Beat 2 eggs with ½ tsp soy sauce. Heat 1 tsp neutral oil in a small frying pan over a medium-low heat, pour in the egg and stir gently until it starts to set, then fold it into a thick, roughly 10 cm square omelette. Cook until firm right through with no wet egg, about 4 minutes. Cool on a plate.

Step 2: Mix ¼ tsp salt into 10 ½ oz cooked Japanese short-grain rice. Lay a large sheet of cling film on the worktop and put a sheet of 2 sheets nori seaweed on it, shiny side down, turned like a diamond.

Step 3: Spread a quarter of the rice in a 10 cm square in the centre of the nori. Layer half the 2 lettuce leaves, half the omelette, half of ½ cucumber and a thin stripe of 1 tbsp mayonnaise, then cover with another quarter of the rice.

Step 4: Fold the four corners of the nori over the filling, one at a time, so they overlap in the middle. A common mistake is overfilling: if the corners won't meet, take some filling out rather than stretching the nori, or it will split.

Step 5: Wrap the parcel tightly in the cling film and set it seam side down for 5 minutes, so the nori softens and seals. Make the second one the same way.

Step 6: With a wet, sharp knife, cut each parcel in half straight through the film. Unwrap at lunchtime, or pack in the film with an ice pack and eat within 5 hours.