01 - Arrange the bread slices on a work surface. Spread 2 tablespoons of fig jam evenly over two slices.
02 - Distribute the softened goat cheese evenly over the remaining two bread slices.
03 - Top the goat cheese with thinly sliced red onion and fresh arugula leaves, if desired.
04 - Pair each jam-topped slice with a cheese-topped slice to create two sandwiches, pressing gently to seal.
05 - Evenly coat the outside of each sandwich with softened unsalted butter on both sides.
06 - Preheat a nonstick skillet or griddle over medium heat. Place the sandwiches in the pan and cook for 3 to 4 minutes per side, pressing lightly with a spatula, until the bread is golden and crisp and the goat cheese has melted slightly.
07 - Transfer sandwiches to a cutting board, allow to cool for 1 minute, then slice and serve warm.