I wanted to share my version.
Right about now, I start hoarding all the Kent mangoes for Chamango/Mangonada, but it isn't until keitt are available that such refreshments become their best.
My first recommendation is to try many types of Chamoy to find which one suits your taste best.
Many are vinegar(acetic acid) based, others are citric acid, or malic acid based. I find that the Organic acid type will affect the preference, with some strongly preferring one type to another.
Chamoy comes from Xi Muoi, a name for Prunus Mume. This fruit is not edible in the raw state and needs pickling to become edible. In Japan the fruit is packed into barrels with salt, which causes juice to come out through osmosis. This juice is called Umezu (Ume vinegar). It is used to pickle a variety of different things including Beni Shoga, one of my all time favorite pickles. Beni Shoga is used to provide a bit of refreshing bite to a heavy Donburi (rice bowl).
In Mexico, the effluent from Saladito manufacturing is use to make Chamoy, a spicy, sour, salty dressing for fruit.
For this recipe I prefer to buy kents that were picked somewhat early, because the starches have yet to convert to sugars, and the normally chalky effect adds a creamy texture to the refreshment.
I first cube and freeze the Kents, then when Keitt season rolls around, I use those as the liquid. Using a powerful blender (750 watts or higher), first put the flesh of a Keitt in the blender. Then add the frozen flesh of a Kent. They should be of about similar proportion, maybe leaning slightly toward the Keitt. Then blend on high until a smooth mixture is formed.
I tried to think of a comparable texture when pouring, and the closest thing that comes to mind is Tororo. Suffice to say, the texture is everything in this recipe. First pour chamoy down the sides of the glass, allowing some to pool in the bottom, then pour in the mango mix.
Stir a little with either a boba straw, or if you can find, a tamarind coated boba straw.
Sprinkle tajin on top, and you're off to the races.