1. Finely chop the onion, then put the mince into a large mixing-bowl and mix in the onion, and raw egg. Next add the HP sauce, mustard and herbs.
2. Pre-heat the grill for 5 mins. When heated, shape the burger mixture into 4 circular blobs (try and compress these tightly as you don’t want the burgers falling appart in the oven) and place on the rack under the grill near the top of the oven.
3. Grill for 3 mins on this side, then turn the burgers over and cook for 2 more mins
4. check the burgers are cooked to the middle by cutting into one and see if it is still pink. if it is then grill for another min or so until it looks ready.
5. Cut bread-buns in half, place burger in middle and add what ever salad or cheese you have, finished with a large dollop of tomato ketchup 😉