Heat butter in a pan over medium high heat.

When hot, add the onion slices in (the onions should sizzle), and reduce heat to medium to avoid burning.

Allow the onions to caramelize for 15 minutes, stirring once every 5 minutes. If pan starts to dry out, add an additional tablespoon of butter to continue cooking.

On tortillas or wraps, place the apple slices, followed by the thyme and shredded Gouda cheese. Add the caramelized onions and place the second tortilla or wrap on top.

In a pan over medium high heat, or on a mini grill, place the quesadilla. Heat through on one side for 3 minutes, then flip and heat through the other side for an additional 3 minutes.

When both sides are crisp and cheese is melted, slice using a pizza cutter.