Heat air fryer to 375 degrees, if preheating is recommended for your air fryer.
Step 2
In a medium bowl, combine the green beans, vinegar, olive oil, red-pepper flakes and garlic. (If there are any nubbins of garlic left after grating, throw those pieces into the air fryer as well; those bits transform into tasty crisps, golden on the outside but still tender and soft inside.) Season the green beans with salt and toss to coat, massaging the garlic onto the green beans.
Step 3
Transfer green beans to the air fryer basket and scrape any remaining dressing on top. Fry at 375 degrees for 8 to 10 minutes, tossing with tongs or shaking the basket halfway through, until the green beans are charred in spots and fork-tender. (If you like your green beans with more bite, fry them on the lower end of this time range.)
Step 4
Transfer green beans and any crisped garlic pieces back to the mixing bowl or to a new serving bowl and top with any remaining sauce from the air fryer. Season to taste with salt and serve hot or at room temperature.