Turn off the heat. Add the brandy to the pan, and allow it to bubble down for a minute. (Be careful: An open flame or spark can ignite the brandy into a flambé. If this happens, just smother it with a lid.) Return the pan to the burner over medium heat, and once the brandy has evaporated add the cream. Cook, stirring, for about a minute, until the cream has reduced to a saucelike consistency. Stir in the rosemary, hit it again with salt and pepper, and set aside to cool.