Mix the olive oil, red wine vinegar, chopped parsley, minced garlic, onion powder, chopped red chili, oregano, salt, and pepper together in a bowl to make the chimichurri. Let it sit for 10 minutes to infuse the flavours into the oil before using.
Season chicken with salt, then pour 2 tablespoons of chimichurri out into a shallow dish and coat the chicken. Marinate for 20 minutes, putting the rest of the chimichurri aside to use later.
On the air fryer, select Roast, setting the temperature to 194°C for about 15 minutes.
Allow it to rest for 5 minutes and spoon the remaining chimichurri over each chicken breast and serve any extra together in a small dip bowl on a serving plate.