Mum was a good solid home cook. As she and Dad had travelled Europe for 6 months in a campervan for their honeymoon instead of having a big wedding (revolutionary in 1959), she was exposed to a wider variety of food than was available in 1950s Australia which meant she was a bit more adventurous than others at the time. She served this dish to the family in the 60s and 70s – I have no idea where the recipe came from but we all loved it. I know many people have a philosophical objection to fruit in savory dishes but I don’t. If you grow up in Australia where fruit is locally grown, plentiful, and cheap, fruit gets put into a wider range of food than it does in the UK. (If you have never had mango with lobster, you have not lived)
If you want to do a vegetarian version, I think chickpeas might be a good substitute for the chicken but do whatever you think is best.