Combine the caramel sauce, thyme sprigs and 2 tablespoons water in a small microwave-safe bowl and microwave until hot, about 1 minute. Cover and keep warm.
Cut the baguette into 4 long, angled slices. Divide half of the cheese among 2 bread slices; sprinkle with half of the chives. Top with the apple slices and the remaining cheese, chives and 2 bread slices.
Melt the butter in a large skillet over medium heat. Add the sandwiches and cook, pressing occasionally with a spatula, until the bread is toasted and the cheese melts, about 4 minutes per side, adding more butter to the pan if needed.
Remove the thyme from the caramel sauce and sprinkle with sea salt. Serve with the sandwiches for dipping.
Photograph by Sam Kaplan
Recipe courtesy Food Network Magazine