Pre-heat oven to 200°C / 425°F / Gas Mark 7.
Wash and cut potatoes in wedges. Brush with a little of the oil, lightly salt and place on a baking tray. Bake for 20 minutes until edges are golden.
In a frying pan sauté onion in oil at a medium high heat.
Brush pork with mustard on one side and press on crumbs.
Place crumb side down in pan with onion and brown to seal in flavour.
Add mushrooms, seasoning and herbs. Turn over meat and continue cooking on a medium heat for 15 minutes depending on the thickness.