Flip the bread slices (butterless sides up), spread apricot jam on one slice and brie on the other. Remove the thyme leaves from the twig by gently pulling downward from the top of the sprig and sprinkle over the cheese.
Put the slices together and place the sandwich in the pan. Cook for 3 minutes per side. Once the bread is toasted + golden and the cheese is melted, remove from the pan and serve immediately.