Method

Put your onions on a hot barbeque with a third of the oil. Let them cook until golden brown. Now add your kangaroo fillet with a little of the oil and pepper. Cook on both sides quickly, about one minute each. Kangaroo meat should be rare. Meanwhile add the mushrooms to barbeque with the final third of the oil. Cook until brown and soft.
Peel and grate one beetroot.
Just before everything is ready on the barbeque, cut your bun in half and toast it on the barbeque.
To assemble – scrape half the mustard on each bun then top with your fillet, then the onion, mushrooms, tomato, beetroot and lastly the lettuce.