Generously butter one side of each slice of bread.

Heat a skillet over medium heat.

Place bread slices butter-side down into hot skillet. Arrange Brie cheese slices on top of each piece of bread. Sprinkle thyme and cracked black pepper over the top.

Spread pear slices in a single layer over the Brie cheese on one slice of bread and top with a pinch of salt.

Flip the slice of bread without pears onto the slice of bread with the pear slices. Continue cooking sandwich until cheese and pear are heated through and cheese is melted, 2 to 3 minutes per side. Transfer to a plate and cut into halves.