I took this way back in 20016, and never did anything with it. Today, though, I was looking at images from that year and decided to play around with it a bit. I also used the PlantSnap app which identified it quickly, and I do hope it is correct. Images online match up, so I’m hopeful.
It’s also called Feijoa sellowiana I believe (but I’m a bit confused about this so perhaps a botonist will help me out), and a common name is pineapple guava. It’s native to South America.