Preheat the air fryer to 380 degrees F (193 C). In a mixing bowl toss the radishes with the oil (or lemon juice for oil-free).
Sprinkle with garlic powder, salt, pepper, and lemon zest, if using, and toss to coat.
Transfer the radishes to the air fryer basket (if using lemon juice be sure to leave it in the bowl). Cook for 10 to 12 minutes, shaking the basket after 6 minutes. Air fryers can vary, so check the radishes after 8 or 9 minutes. For crisp-tender radishes reduce by a minute or two, or cook longer for soft, tender radishes.
Serve hot with a squeeze of lemon, fresh parsley, or your favorite dipping sauce.
Oven Roasting Instructions
No air fryer? No problem.Preheat the oven to 420 degrees F, and line a baking sheet with parchment paper.Arrange the seasoned radishes in a single layer, cut-side down. Bake for 15 to 20 minutes or until they are as tender as you like. It's a good idea to check on them at the 10 minute mark, flipping them if desired.
Storage and Re-heating
Roasted radishes are best right after cooking, but we even love them after they've cooled to room temperature. If you have leftovers, store in an air-tight container in the fridge and reheat in the microwave or air fryer.