Hello,

In my country (Nicaragua) we call that fruit "Pithaya" and we eated when is riped, it has a purple raddish color inside and is delicious, we prepared like drink, a Juice, when the fruit is ripe, you thake the inside with a spoon,  cut it in small pices put in a blender with water, sugar and alittle of lemon juice to add it a delicios acid flavor the the drink, when you finish you can drinked with ice or refrige.