Slice the tomatoes into 1/4" slices laying the slices flat on a layer of paper towels. Gently pat dry.
3 large ripe red tomatoes
Add the buttermilk to a shallow bowl, and set aside. Add both the cornmeal and panko to another shallow bowl, whisking together until evenly combined, and set aside. Add the flour to a plate, and set aside.
1 cup self rising yellow cornmeal, 1 cup panko bread crumbs, 1 cup buttermilk, 1 cup flour
Working with one tomato slice at a time dip it in the flour to evenly coat on both sides. Shake off excess then dip it in the buttermilk, turning to coat evenly. Transfer to the panko mixture, turning to coat evenly and pressing the breading in- if needed to ensure it sticks evenly.
Transfer the breaded tomato slice to a parchment paper lined baking tray, and repeat until all slices have been evenly coated and are also on the prepared baking sheet.
Liberally spray the basket of your air fryer with non stick cooking spray. Cook in batches of 4-5 so you don't overcrowd the air fryer basket. Spritz the tops with non stick cooking spray.
Cook at 390° for 5-7 minutes. Using tongs gently flip each slice over, then continue cooking another 5 minutes.
Transfer the fried red tomatoes to a waiting plate using tongs, then sprinkle with salt.
3 tbsp course salt
Continue cooking until all the tomatoes have been air fried, then serve immediately.