This one is great but it’s not healthy at all. It’s a one-way ticket to Diabetesville:
https://www.muydelish.com/traditional-mexican-horchata/#recipe
The kind that is good for you is the original, Spanish recipe using tiger nuts. This is the recipe we use:
https://www.alphafoodie.com/homemade-tiger-nut-milk-horchata-de-chufa/
Grind/blend the tiger nuts in water. Pour all of it into a cotton bag (like people use for Greek yogurt) or cheese cloth over a bowl, then squeeze the hell out of it until all the tiger nut milk is out. I still use a cotton bag, but cranking it with a press is WAY easier, faster, and more effective.