Roast Rib of Beef with Port and Stilton Gravy

INGREDIENTS

• 1 teaspoon red currant jelly
• 1 tablespoon all-purpose flour
• Port and Stilton gravy, recipe follows
• Kosher salt and freshly ground black pepper
• 4 1/2 ounces blue cheese (recommended: Stilton)
• 2 onions, peeled, cut into 1/3-inch (1 cm) rounds
• 1/2 cup (125ml) ruby port
• 1 tablespoon cooked onions from the roast beef tin, optional
• 2 tablespoons garlic oil
• 8 pounds (3.8kg) beef forerib (4 rib joint) (recommended: Scotch or Black Welsh)
• Extra juices from the roast beef tin and carving
• 2 cups (500ml) organic beef stock, "fresh" from a shop-bough tub
• 1 1/2 teaspoons maldon salt or 3/4 teaspoon table salt
• 2 tablespoons fatty juices, reserved from the roast beef tin
• 1/2 teaspoon cayenne pepper
• 1 teaspoon dried thyme