1. Preheat the oven to 350°F.
2. Season the pork fillet with salt and pepper. Transfer it to a skillet with melted butter and brown the meat. Place it on a baking sheet and bake for 20 minutes.
3. Add the apple quarters to the skillet and brown them.
4. Pour in the demi-glace and simmer for 2 minutes.
5. Remove the pork from the oven. Slice into 8 equal medallions. Serve with the roasted caramelized apples and garlic cooking juice.