Longhorn Beef Sirloin Recipe with Charred Onions - Great British Chefs

Ingredients

• 600g of aged sirloin of beef
• 50g of salted butter, high-quality
• olive oil
• flaky sea salt
• 5 Tropea onions, large
• red wine vinegar
• salt
• 1 bunch of parsley, small, finely chopped
• 100g of walnuts, toasted and finely chopped
• 6 pickled walnuts, finely chopped
• 400ml of light olive oil
• 1 tbsp of Dijon mustard
• 1 tbsp of capers, finely chopped
• 1 anchovy, finely chopped
• lemon juice, if needed
• watercress