Peel feijoas, saving the skin. Roughly chop fruit and set aside.
Put feijoa peel and apple into a saucepan, then barely cover with water. Cook until soft and mushy. This will make the cooking liquid for the feijoa.
Strain cooked fruit through a fine sieve into a large heavy-bottomed pot, making sure to push down hard on the apples to get out all the juice. Add feijoa mixture to liquid and cook until soft.
Push feijoa mixture through a sieve, mash or use a stick blender to produce feijoa pulp.
Add sugar to feijoa pulp and stir until dissolved.
Cook slowly on lowest heat, stirring every 2-3 minutes until thick. This will take about 2 hours – when it’s ready, the spoon will leave a path in the mixture and will start to come away from the sides. Mine didn’t get that thick mostly because I was too impatient to wait any longer but it still set well.
The recipe said to line a slice tin with baking paper and quickly pour paste in. Smooth the top.
Place aside to set, then cut into squares, wrap in paper and store in an airtight container in the fridge.
