Barbecued hanger steak with cacio e pepe mushrooms – Gourmet Traveller

Ingredients

• 150 gm unsalted butter, softened
• ½ cup flat-leaf parsley, finely chopped and loosely packed
• 40 gm ( ½ cup) finely grated pecorino
• 2 garlic cloves, crushed
• grated zest and juice of 2 lemons
• 2 tsp mixed whole peppercorns, coarsely crushed, plus extra, to serve
• 500 gm hanger or flat-iron steak, trimmed, at room temperature
• 800 gm mixed mushrooms, such as king brown, Swiss or button, trimmed
• ⅓ cup sage leaves, loosely packed
• Baby cos salad
• 80 ml (⅓ cup) extra-virgin olive oil, plus extra for drizzling
• 2 tbsp Dijon mustard
• 200 gm baby cos, leaves separated
• 1 cup mixed baby herbs, such as chervil, tarragon, parsley, coarsely chopped