Spoon a tablespoon or two of the pesto on one piece of bread. Layer with the chicken, pears and sliced brie. Place another piece of bread on top and place back on the grill pan. With the heat off, place a small skillet on top and press down until the cheese starts to melt. I turned the heat off because I didn't want to burn the bread, but the heat from the cast iron pan melts the cheese at the same time.