Heat a non-stick skillet over medium heat and lightly coat with cooking spray or butter.

Place one flour tortilla in the skillet.

Spread the prepared tuna salad evenly over the tortilla.

Sprinkle the shredded cheddar cheese over the tuna salad.

Cover with the second flour tortilla.

Cook until the bottom tortilla is golden brown and the cheese is melted, about 3-4 minutes.

Carefully flip the quesadilla using a spatula, and cook the other side until golden brown, about 2-3 minutes.

Remove from the skillet and let it cool for a minute before cutting into wedges.

Pack in a lunchbox with a side of carrot sticks or apple slices for a balanced meal.