In a large skillet, heat 1 tablespoon of olive oil over medium heat.

Add 1 cup of fresh corn and 1/2 cup of sliced red onion to the skillet and sauté for about 5 minutes.

Remove the skillet from heat and transfer the corn and onion mixture to a bowl, set aside.

Return the skillet to stove and place one tortilla in it, sprinkle half of 1/2 cup of grated cheddar cheese evenly over it.

On one side of the cheesy tortilla, layer half of the sliced heirloom tomatoes and half of the corn mixture, top with half of the fresh basil leaves.

Cover the skillet with a lid and cook for 1-2 minutes, or until the cheese is melted and bubbly.

Gently fold the uncovered half of the tortilla over the filled side and cook for an additional minute until golden brown.

Remove the finished quesadilla and repeat the process with the second tortilla using the remaining filling ingredients.

Once both quesadillas are cooked, cut each one into wedges, and serve with fresh salsa or guacamole.