Instructions

1. If the berries are frozen, thaw them completely and tip the juice in with them. Most of the colour lives in that juice, and pouring it down the sink leaves you with a dull brown sheet.
2. Blend only until the seeds are the last texture standing. Raspberry and blackberry seeds will not break down, and chasing them warms the puree and flattens the fresh smell you are trying to keep.
3. Push half the puree through a sieve if you want a smoother roll, then stir it back in. Removing every seed costs you most of the body, so half is the compromise worth making.
4. Spread the puree on a solid liner at an even depth, working outwards from the centre and leaving a finger of bare sheet all round. That bare margin is where the peeling will start.
5. Knock the tray down on the bench, then look across the surface at eye level. Thin patches show up as translucent windows, and those windows go brittle long before the rest is ready.
6. Dehydrate at 40 °C for 7 hours. The colour deepens from red towards black as it goes, which is sugar concentrating rather than anything scorching.
7. It is finished when a fingertip pressed into the middle leaves no print and a corner lifts cleanly. Anywhere still glossy is still wet, and that patch is what moulds once it is rolled.
8. Peel it warm, lay it on baking paper, and cut through both at once with scissors. Banana makes this stickier than most leathers, and the paper is all that keeps a roll from fusing into a lump.
9. Jar the rolls with a desiccant sachet and eat them inside a month. Honey pulls damp out of the air, and left in an open bag on the bench they go limp in a week.