Steak and onion in a jacket

Preheat oven to 200°C (400°F, gas mark 6). Scrub the potatoes and place in the oven for 1 hr 15 mins or until soft throughout. After the potatoes have been cooking for 45 mins, heat the oil and gently fry the onions until golden brown and soft (this should take about 15 mins). Increase the heat, add the steak and fry for 3-4 minutes or until cooked. Stir in the mustard, wine and seasoning, and continue to cook for 1 min. When the potatoes are cooked, cut them almost in half lengthways and spoon in the steak and onion filling. Serve immediately with freshly chopped parsley