Put the bananas in a 10-inch heavy skillet with the butter, brown sugar, liqueur and nutmeg and set over high heat. Once the sugar starts to dissolve, begin spooning the sauce over the bananas, flipping them after 1 minute. Remove from the heat when the sauce begins to thicken and bubble. Carefully pour the bourbon into the pan and ignite with a long match or stick lighter. Continue to cook until the flames die out and the sauce coats the back of a spoon. Serve immediately with ice cream, waffles or crepes.