Method:
1 Combine onion, garlic, mince, mustard and herbs in a bowl, season with salt and pepper, shape into a large pattie.
2 Heat oil in a frying pan over medium heat and cook burger for 4-5 minutes each side or until cooked to your liking.
3 Heat a char-grill pan over medium heat, drizzle the sourdough with olive oil and char-grill for 2-3 minutes each side or until toasted. Add the bacon and onion rings to the pan and char-grill for 4 minutes turning, until golden and tender.
4 Place 1 slice of bread on a plate, top with the burger, bacon, onion rings, rocket and tomato, drizzle with olive oil and season, sandwich together with remaining toasted bread.