We have a lemon tree, an orange tree, and a feijoa tree in our yard. These are feijoas! It's a very strange little fruit that I can't quite describe. The internet says they have a "unique, aromatic tropical flavor described as a blend of pineapple, strawberry and guava with a tangy or slightly minty, perfumed aftertaste." I'm not sure how I feel about them yet but I bet they'll make a great crisp!