1. Place the onion, spinach, parsley and carrot pieces or strips in the bowl of a food processor and process until fine. Turn out into a large bowl, add the beef mince, Worcestershire sauce and eggs and season with salt and pepper. Mix well, but don’t overmix.
2. Use a 80ml (c) measuring cup, spoon out the mince mixture and shape into patties. Place on a greased baking sheet and refrigerate until just before cooking.