This Aussie Mushroom Burger features flavours iconic to Australia with the beetroot relish, vintage cheddar cheese, red onion and a big BBQ flat mushroom.
Preheat the barbecue plate to medium-high heat. Spray prosciutto and onions with olive oil. Barbecue prosciutto for 1 minute each side until golden, transfer to a plate. Barbecue onions 5-8 minutes or until tender, transfer to a plate.
To prep the mushrooms, there is no need to wash or peel the mushrooms, simply wipe with a damp cloth if needed. If the stalk is long, you can trim it with a knife, so if sits flat on the BBQ. Spray mushrooms lightly with oil and grind a little salt and pepper on each side. (An added option is to sprinkle them with a little rosemary too)
Barbecue mushrooms stem side-up 4 minutes, turn over and barbecue 3 minutes, or until tender.
Turn mushrooms over, top evenly with onions and cheese. Close barbecue hood (or cover mushrooms with an upturned roasting pan) cook 2-3 minutes until cheese is melted
Combine beetroot relish and mayonnaise. Spread over bun bases. Top each with salad leaves, tomato slices, prosciutto and mushrooms. Season to taste and serve.