Heat olive oil in a large pan over medium-high heat. Once the oil is hot, place the sliced onions in the pan and add in the pinch of salt. Reduce heat to and cook them until soft but not brown, about 10-15 minutes. Stir occasionally. 

After the onions are softened and translucent, add in the pears, balsamic vinegar, apple juice and sugar. Cook at a low heat until the liquid has evaporated and the onions are browned and caramelized. Stir every once in awhile to prevent them from sticking to the pan, about 30-45 minutes.

Remove from heat and add in the thyme. Set aside.

Lightly brush flatbreads with olive oil and top with the cashew mozzarella and the caramelized pears and onions. Bake at 350 degrees F for 10 minutes or follow the cooking instructions on your flatbread package. 

Serve warm and enjoy!!!