Oddly enough, they went with American cheese rather than a more Italian provolone or mozzarella. The rest of the burger is pretty run-of-the-mill, if minimalistic: an Australian beef patty, chicken crisp (a halal stand-in for bacon), and toasted bun.
The tagline they're running is: "So good, you'll go, 'Mamma Mia!'"
It seems a little uninspired. Maybe they should have looked to Boston Pizza's Pizzaburger for inspiration. I like the name though.