Step 1

Preheat oven to 200°C/400°F.

Step 2

To make anchovy butter, combine ingredients in medium bowl. Shape butter mixture into a log on large piece of plastic wrap. Roll to enclose; twist ends to secure. Refrigerate 30 minutes.

Step 3

Rub beef with 1 tablespoon olive oil, season. Heat oiled medium ovenproof frying pan over high heat; cook beef until browned both sides. Transfer to oven; roast, uncovered, 15 minutes. Reduce oven to 180°C/350°F; roast a further 15 minutes. Cover beef, bone-side down, loosely with foil; stand 15 minutes.

Step 4

Meanwhile, make sautéed mushrooms. Heat vegetable oil in large frying pan; cook mushrooms, in 2 batches, over high heat until softened. Remove from pan. Heat remaining 1 tablespoon olive oil in same pan; cook shallots and garlic until shallots are soft. Return mushrooms to pan, stirring, until heated. Remove from heat, stir in vinegar and parsley. Season to taste.

Step 5

Serve beef with sautéed mushrooms and slices of anchovy butter. Serve with steamed green beans, if liked.