Preheat the oven to 200°C.
Layer basil and brie onto flattened pork, roll it up, season, and refrigerate in clingfilm for five minutes.
Coat the pork roll in flour, then beaten egg, and finally breadcrumbs, pressing firmly to adhere.
Sear the pork in olive oil for two minutes per side, then roast in the oven for ten minutes.
Melt butter with oil, thyme, and garlic, then fry potato rounds for two minutes per side before roasting for fifteen minutes.
Sauté garlic and onion in butter, then simmer with mushrooms and cream for five minutes.
Plate the mushroom sauce, top with sliced pork, and serve with the warm fondant potatoes.