How to Make It
Spray a skillet with nonstick spray. Place four slices of bread in pan over medium-low heat.
Top each bread slice with 1/4 cup caramelized onions and 1/4 cup cheese. Sprinkle each sandwich with 1/4 tsp fresh thyme.
Heat on medium-low until the bread is toasted, onions are heated through, and cheese begins to melt. Top with additional bread slice.
Flip each sandwich over and heat until cheese is melted and bread is toasted. Serve immediately.