This fruit is white, egg-shaped, and about the size of a small apple. It has a tough outer skin that can be peeled with a knife, like a mango’s, but has white flesh and a very juicy, watery interior full of a softer white flesh and small, edible seeds.
It’s also mostly bland and lightly bitter; it holds the distinction of being the only distinct kind of fruit I know of so far that I would not like to eat again. It was purchased at a Smith’s in Great Falls that was somewhat lacking when it came to labeling its produce.
The description of the edible part sounds like Dragon Fruit, but I’m doubting that ID, because I can’t find an example with a white outer skin - they’re all gaudy pink or yellow.
I think it might have been a golden egg fruit, which is a type of eggplant, and is white and bitter when not ripe. The best info I could find is here, though there’s no description of the seeds.
I was going to say pepino melon as well. They don’t always have pronounced stripes, and they do show up in US supermarkets from time to time. And the flavour, as you noted, is mostly watery. However, you didn’t mention the hollow interior.
Also the season is wrong - they’re a fall fruit and they don’t keep well past ripening. You just can’t get them this time of year. August is the earliest month for them in the northern hemisphere.
