The flan can be baked in either a wide glass baking dish, or glass mixing bowl or 6 ramekins.
Heat 4-5 cups of water in a pot on stovetop for the water bath.
Put a heavy skillet or saucepan over medium heat for 30 seconds. Add 1/2 cup sugar. With the back of a wooden spoon, keep sugar moving constantly in skillet. As the sugar begins to melt, pour in the triple sec. Keep moving the spoon until sugar is completely melted, and of a rich medium brown color (caramelized).