Preheat your air fryer to 400°F (200°C) for a few minutes.

While the air fryer is preheating, prepare the plantains. Start by cutting off the ends of the plantains, then make a shallow cut along the length of each plantain, just enough to penetrate the skin.

Peel the plantains by inserting your thumb into the cut and gently pulling the skin away from the flesh. Cut the peeled plantains into thick slices, about 1 inch (2.5 cm) thick.

Line your air fryer basket with air fryer liners or parchment paper to prevent sticking. Lightly coat the liners with cooking spray.

Arrange the plantain slices in a single layer in the lined air fryer basket. It's okay if they overlap slightly, but avoid overcrowding.

Lightly spray the tops of the plantain slices with cooking spray and sprinkle them with regular table salt.

Place the basket in the preheated air fryer and cook for about 10 minutes.

After the initial 10 minutes of cooking, gently take out the plantain slices from the air fryer. Place them on a baking sheet lined with parchment paper or a paper towel. Then, cover them with another layer of parchment paper. Applying pressure on the tostones using a large casserole dish or a similar flat object. Press down firmly to flatten them, making them thinner, wider, and less defined in shape.

Return the plantain slices to the air fryer basket using tongs or a fork. Lightly spray the other side with cooking spray and sprinkle with regular table salt.

Return the basket to the air fryer and continue cooking for another 5 to 10 minutes, or until the tostones are golden brown and crispy.

Once the tostones are cooked, remove them from the air fryer and transfer them to a plate lined with paper towels to absorb any excess oil.

While the tostones are still hot, sprinkle them generously with flaky sea salt, such as Maldon sea salt. The contrast between the crispy texture and the flaky sea salt adds a delicious touch.

Serve the tostones with your favorite pico de gallo and Colombian aji on the side for dipping. Enjoy them as a tasty snack or as a side dish to complement your meal.