So, the first thing you need to do is cut the leftover chicken into slices or pieces, using a knife

Then, place a large pan on the stove and heat it. I suggest you to add ¼ tsp vegetable oil because this will make your flat bread a little crispy

Using a knife, make a cut on the flat bread up to its center, this will allow you to wrap it afterwards

Place the flat bread in the preheated pan. Spread ketchup

Add the slices of leftover chicken and the cheese

Optional: you can add your favorite veggies

Leave the cheese to melt for 1-2 minutes, then start to wrap the flat bread until you achieve a triangle shaped quesadilla

Place the quesadilla on a plate and leave it to cool for 5-10 minutes before serving it. You can dip it into a sauce, if you want.