Hishi mochi (diamond rice cakes)

Step 1: Line a 15 cm square tin with cling film and dust the base with a little 2 tbsp potato starch (katakuriko).

Step 2: For the green layer, whisk 3 ½ oz shiratamako (glutinous rice flour), 1 oz caster sugar and 1 tsp matcha powder in a microwave-safe bowl, then stir in ½ cup water a little at a time to a smooth, thick batter with no lumps.

Step 3: Cover loosely and microwave at 600–800 W for 1½ minutes, stir hard with a wet spatula, then microwave for another 1–1½ minutes, until the paste turns from opaque to glossy and slightly translucent and stretches in long strands.

Step 4: Knead the hot mochi in the bowl with the wet spatula for 1 minute until smooth, then press it evenly into the tin with damp fingers. Common mistake: dusting starch between the layers. It stops them sticking, and the finished diamonds slide apart, so only dust the outer faces.

Step 5: Make the white layer the same way with 3 ½ oz shiratamako (glutinous rice flour), 1 oz caster sugar and ½ cup water, microwaving until glossy and stretchy, then spread it straight over the green layer while both are warm.

Step 6: Make the pink layer with 3 ½ oz shiratamako (glutinous rice flour), 1 oz caster sugar, ¼ tsp beetroot powder and ½ cup water, cook it the same way until the colour deepens and turns translucent, and press it over the white layer.

Step 7: Smooth the top with damp fingers, dust with a little more starch, cover and leave at cool room temperature for at least 1 hour, until firm enough to cut cleanly.

Step 8: Turn the cake out onto a board dusted with the rest of the 2 tbsp potato starch (katakuriko). Cut it into 4 cm strips, then cut across at an angle to make diamonds, wiping the knife with a damp cloth between cuts.

Step 9: Brush off excess starch and arrange the diamonds with the pink layer on top. Eat the same day; mochi hardens in the fridge, so keep it covered at room temperature and toast any leftovers.