The Quiznos Classic Italian is a cold sub's parts list run through a conveyor toaster, and the heat is what defines it rather than the cured meats inside. Genoa salami, pepperoni, ham, and capicola are layered with mozzarella on a sub roll, dressed with a red wine vinaigrette, and then the assembled sandwich is sent through an oven that browns the roll and renders the cured pork while it melts the cheese. An Italian sub is normally a cold construction whose appeal is the sharp interplay of room-temperature meats and a last-minute dress; toasting it changes the chemistry entirely, softening the salami's edge, loosening the pepperoni's fat, and turning the dressing from a bright accent into something that cooks into the bread. The toast is the whole point, and it is what separates this build from the cold Italian it descends from.
The craft is in surviving the oven without going to grease or cardboard. The meats are sliced thin so they heat through fast on the short pass rather than tightening into leather, and they are shingled so each bite carries all four instead of a band of one. The mozzarella is chosen for melt behavior over flavor, laid against the meats so it flows down through them and binds the structure as it goes through the heat. The roll has to have enough crumb strength to take a hot, oil-slicked load and a blast of dry heat and still be liftable, because a thin roll scorches and a dense one armors the sandwich. The red wine vinaigrette is the structural counter and the timing decision in one: it goes on before the toast so the acid penetrates the warming meats and cuts their rendered fat from the inside, which is a different job than a cold sub's finishing splash of oil and vinegar performs.
The variations are mostly the dressing and the heat level of the pass, plus leaner builds that drop the pepperoni and hotter ones that add banana or cherry peppers to the toast. The toasted Italian sits inside the broad American sub, hoagie, hero, and grinder family, where a long roll is layered the length of it and built so every bite holds the whole sandwich, conducted under a dozen regional names and a dozen house dressing protocols. Each of those is a codified build with its own partisans and deserves its own article rather than being crowded in here.