Preheat the oven to 350°F Take a large piece of foil, fold in half and place on a baking sheet.
Place the seasoned flour on a plate and use to coat the pork chops.
Heat the oil in a frying pan and quickly sear on both sides until golden brown, then place side by side inside the folded foil. Season to taste.
Melt the butter in the pan, stir in the onion and mushrooms and saute for a few minutes until tender. Season to taste and spoon on top of the chops. Mix the cream with the mustard in a small bowl and drizzle over each chop.
seal the edges of the foil together with a double fold, making sure there will be plenty of room for expansion.
Bake for 45-50 minutes or until the parcel has puffed up.
Open at the table for maximum effect and serve, spooning over all the delicious juices.