Preheat the oven to 80°C fan forced. Line two, 27cm x 42cm (base) baking trays with a silicone matt (see tip) or baking paper lightly greased with canola oil.
Place the mango, lemon juice and caster sugar in a blender or food processor. Blend or process until smooth. Pour into a jug. Pour half into the centre of each lined tray, then spread evenly to cover the matt or paper until about 3mm thick. Bake for 3½-4 hours or until centre is feels a little bit sticky but not wet to the touch (the edges should lift off the matt or paper easily). Set aside to cool for 1 hour or until completely cool.
Place a sheet of baking paper over the surface of one tray then turn out onto the bench. Carefully peel the silicon matt or paper from the mango. Use scissor to cut crossways into 6cm wide ribbons, then roll up and secure with kitchen string. Repeat with the remaining tray. Store roll ups in an airtight container in the fridge for up to 6 weeks.
TipSilicon matts are inexpensive online for from kitchenware stores. They are reusable.
TipOnce the trays have cooled, if you find the mixture is still a little sticky in patches you can place the cut strips back into an 80°C fan forced oven to continue drying.