Steak diane with roast potatoes

Ingredients

• 300g waxy potatoes (such as charlotte), cut into wedges
• Olive oil for drizzlingApple-converted-space
• 4 garlic cloves, unpeeled and bashed
• 2 fresh rosemary sprigs
• 2 fresh thyme sprigs
• 2 x 200g British dry-aged sirloin or rump steaks
• ¼ tsp black peppercorns, crushed in a pestle and mortar
• ½ tsp green peppercorns, crushed in a pestle and mortar
• Watercress to serve
• Splash olive oil
• 2 shallots, finely sliced
• 2 tbsp brandyApple-converted-space
• 150ml beef or chicken stock
• 3 tbsp crème fraîcheApple-converted-space
• 1 tbsp hot horseradish cream (from a jar)