A really delicious, rare nightshade berry! Greenberry is a native Australian plant that produces clusters of plump green berries with cute hat-like calyxes. The ripe fruit is soft and flavorful, with gooey green flesh. Unripe fruit should not be consumed. It’s simple to determine ripeness as the berries will easily come off the plant or fall off like ground cherries. They’re a great color accent served with yogurt, granola, and other fruits.

I’m not sure who the original Australian source was, but Fair Dinkum Seeds has a lot of information on them.
https://fairdinkumseeds.com/products-page/ethnobotanical-or-medicinal-plants/green-berry-nightshade-solanum-opacum-morelle-verte-seeds/
 
Seeds, description, and photos from Wambus: https://www.instagram.com/grumpenstein3d/