After not knowing what they were and discovering they were guavas - I went In search of a recipe for guava jelly.
I found a very simple one
Cut the guavas into one inch chunks throw into a pot and cover with water
Cook until the fruit is very soft.
Strain liquid through Muslin let cool and then squeeze all the liquid out of the Muslin.
Measure the liquid and for every cup add a cup of sugar
For every cup of sugar add the runs and juice of a quarter of a lemon - it as I did an orange.
Then boil until it thickens and coast the back of a spoon evenly.
Pour into sterilized warm jars.
I froze the fruit and then cut it and the fresh fruit from today. It worked so all good.