You don't need a stodgy bread roll with this recipe. Simply wrap up your burger with lettuce leaves for a tasty, low carb bunless burger, perfect for BBQs.
Preheat the grill to a medium heat. Heat the olive oil in a large frying pan and cook the onions with pinch of salt for 5 minutes until they are both soft, and caramel brown in colour. Don’t let them get crispy! Place the onions on a plate for later and keep the pan handy for cooking mushrooms. For the burgers, put the beef, salt and pepper in a large bowl. Mix by hand to combine well and then form into 2 pattys. Top with some of the brie and onions, then top with the other half, placing the second patty on top of the cheese and onions, to form your burger! Place the burgers under a preheated grill and cook each side for 4-5 minutes. While the burgers are grilling, cook the mushrooms in a little butter which takes 2-3minutes. Once the burgers are cooked remove them from grill. Layer mushrooms and onions over the cooked burgers and serve with a side salad.