While this recipe is for shrimp tempura, the shrimp may be replaced with other things. Those things should, however, be fairly low in moisture such as carrot or zucchini strips. This can also be made gluten free by substituting the flow with a gluten-free option. I have tried with rice flour and it tastes basically the same, although less water should be added. The potato starch may also be substituted with another powdered starch such as corn starch. The batter may seem too thin when covering the item being fried, but will puff up. Additional batter may be drizzled on the items after being put in the oil, but too much can reduce the crunchiness of the coating.
A full written recipe may be found here: https://cook.karylstein.com/g/family/r/shrimp-tempura