Rib roast with potato gratin recipe | Gourmet Traveller

Ingredients

• 2 tbsp olive oil
• 2 tbsp chopped rosemary
• 2 tsp Dijon mustard, plus extra to serve
• 3 anchovy fillets, crushed with a mortar and pestle
• 1 rack of beef (also known as a standing rib roast), with at least 5 ribs (4.3kg)
• 3 onions, thickly sliced
• Potato gratin
• 500 ml pouring cream
• 4 garlic cloves, crushed
• 5 Desiree potatoes (about 2kg)
• ½ nutmeg