Club soda gives the batter a lighter texture so this tempura fries up extra crisply.
Whisk together egg yolk, salt, and club soda. Gently fold in rice flour or cornstarch.
Heat 1 inch oil to 375 degrees in a high-sided skillet Dip vegetables in batter and fry in batches until tender and crisp, 3 to 5 minutes. Drain on paper towels. Sprinkle with salt.