10-30 minutes. The cooking time will vary depending on the tool used to cook the beef knuckle. When using a pressure cooker to cook beef knuckle, continue to cook for 10 minutes after the cooker is gassed. When using a regular pot to cook beef knuckles, you need to cook for 20-30 minutes. Before cooking, you need to clean and blanch the beef knuckles in water, then rinse with cool water. Cow's trotters can be used to make cold cow's trotters, three fresh cow's trotters and other delicacies.