Heat a drizzle of oil in pan used for pork over
medium heat. Add minced onion and chopped
rosemary. Cook, Stirring often until onion is
softened, 2 -3 minutes. Add demi-glace and 1/4
cup water. Bring to a simmer and cook until
slightly thickened, 3 - 4 minutes. Turn off heat
and stir in 1 TB butter until melted.