Using clean hands combine mince, smoked paprika, grated zucchini and 1 tablespoon of BBQ Sauce in a large bowl. Shape into four 2cm-thick patties.

Heat a large chargrill pan over medium-high heat, brush patties and mushrooms lightly with oil. Cook mushrooms for 4-5 minutes each side or until mushrooms are lightly charred and tender. Cook burgers for 4 minutes or until underside is lightly charred. Turn burgers and cook for 2 minutes. Top each burger with a slice of cheese and cook for a further 2 minutes or until burgers are cooked through and cheese is melted. Cook onion rings for 2 minutes each side or until lightly charred.

Meanwhile, combine Tomato Sauce and remaining BBQ sauce in a small bowl.

To serve, top each mushroom with avocado, rocket, sliced tomato, a burger patty and onion rings. Serve drizzled with the sauce.