A "toastie" is essentially what we think of as a grilled cheese sandwich.
The Bacon, Macaroni & Cheese Toastie is pretty much as descriptive a name as you're going to get. It consists of a two-cheese mac and cheese topped with bacon and sandwiched by two slices of grill-pressed bread.
Corn & Cheese Champignon Toastie, which features champignon mushrooms, sweet corn, and melted white cheese between two slices of grill-pressed bread.
For those who prefer the more conventional, they also have a ham, cheese, and egg toastie.
Photo via McDonald's Hong Kong.