Separate the lettuce into large leaves,wash well,spin and refrigerate until ready to serve. Combine the beef mince with the salt and pepper and mix without squashing the mince together too much. Roll the mince into balls a little larger than golf balls and chill in the fridge for about 10 minutes.
Heat a large frying pan over medium-high heat and add a little olive oil. Squash a few of the balls onto the pan to create small patties,but do not overcrowd. Fry until cooked to your liking,about 3 minutes on each side. Repeat for the remaining patties,and keep warm until ready to serve. Add the onion slices to the frying pan and cook (adding more oil if necessary) over medium heat for about 3 minutes per side until well-browned and cooked through.
For the burger sauce,combine all the ingredients and stir to combine. To serve,place the lettuce,burger patties,grilled onions,cheese,cucumber,tomatoes and burger sauce on the table. Everyone can wrap their own meal.
If you like this recipe,try myeasiest-ever cheeseburgers.
Adam's tip:For burgers or dumplings,cheap mince is always a great option. Mince is graded by its fat content,and you want something of around 20 per cent – or even higher.