Heinz [Seriously] Good Truffle Mayonnaise Burgers with Mushrooms
In a large bowl, mix all the burger ingredients together until combined. Form 4 patties with the mixture, indenting the centre with your thumb.
In a saute pan, melt your butter. Add your onions and cook over a low-medium heat until soft and caramelised, about 20 mins. Add your garlic, cook out for 1 min then add your mushrooms. Season with salt and pepper, then cook out over a medium-heat heat for 5 mins until cooked. Add your herbs and stir to combine.
Grill the burgers, until cooked through, about 8 minutes. Place a piece of cheese on for the last 30 seconds and cover with a lid to melt.
Spread the base of your buns with truffle mayonnaise. Top with the burger and cheese. Add you onions and mushrooms and then top with the other half of your bun.