Melt butter in the oil in a large deep skillet over medium high heat. Season chops with salt and pepper and brown them, about 2-3 minutes on each side. Reduce heat slightly if the chops brown too quickly. Remove chops from pan and pour off most of the fat. Add green onions or shallots and cook on med high heat until softened, about 1 minute. Add wine and bring to a boil, scraping the brown bits from the bottom of the pan. Stir in the stock and return chops to the pan. Bring sauce to a simmer and cook until chops are tender, about 15-20 minutes. Remove the chops to a warm platter;cover with foil to keep warm. Raise the temp of the pan to boil the pan juices,reduce the juices by 1/2, about 2 minutes. Add the cream and boil 2 minutes more, until sauce reduces and thickens. Remove from the heat and whisk in mustard and parsley. If you want, add more mustard to taste. Spoon sauce over chops and serve.