They use Italian stuff. In some parts of Italy, southern boot, they eat a lot of spicy stuff just like Spanish food
Speaking of Sicily only:
The "spicy" and "southern boot" that
@Twowaxhack is talking about is "Calabrian Peppers".
What Are Calabrian Chiles and How Are They Used? Did not see any of these anywhere, and we looked. Of course, I was not in Calabria. About the only "spicy" thing on any menu I saw was "Pizza Diavolo" which jokingly was hardly hot; it was simply pizza topped with a spicy pepperoni, that wouldn't even raise an eyebrow on those Americans used to hot and spice Indian, Mexican, Thai, or similar foods. In fact, the red pepper flakes that many Americans like on their pizza (myself included, often) provides a greater kick.
As for the eggplant,
@havasu in Sicily it is a nearly a "national" dish when served as caponata appetizer. There are as many versions of caponata as there are cooks. Everyone makes it slightly differently, but eggplant, celery, tomatoes, capers, olives, sugar and often with pignoli (pine nuts). Some add sweet red peppers, and other ingredients that may be on hand. We had this nearly every day, as it was on every menu without exception. It was front and center along with olives on every appetizer plate, along with panelle, which are chickpea fritters. In a couple of instances there was a version of what you might call eggplant parmigiana but it was quite different than what you'd see here in the USA.
The other grand use of eggplant is in Pasta Alla Norma, a pasta dish made with eggplant.
Pasta alla Norma Is the Ultimate Taste of Sicily Though it originates from Catania, it was on every menu on the island. Even
Pizza Alla Norma. Legend has it that the black skin of the eggplant is supposed to represent the lava stone of the Catania region, from Mt. Etna; the red sauce the fire of the volcano, and the white ricotta salata the snow that is on the top of Mt. Etna during the winter. We had it with many different kind of pasta, but the most popular serving was with rigatoni.
Interestingly, the use of the word "pasta" is rare; almost always "spaghetti" or "macaroni" or the specific pasta shape.
Those "Italian Tacos" are the invention of an expat Italian. A number of those ingredients are simply not available easily.
My friend who is from Messina but has travelled around, said "if you ask for pineapple on your pizza you will be thrown out of the restaurant"; it would be a huge insult to the pizzaolo. Most Italian food in Sicily is simple and elegant; only in the hands of "inventive chefs" do things get weird and complex. Take Olive Garden for example. I was there merely once many years ago to realize this "son of Sicily" does not need to have his intelligence insulted by such corruptions, endless breadsticks notwithstanding. Those Olive Garden chefs
simply make things up that don't exist, using Italian ingredients (cheese, pasta, oregano, basil, etc.) and give them Italian names. It's ridiculous. Ditto for this new-wave invention, "vodka sauce". Puleeze...if Sicilans ever were "rich enough" to have vodka on hand the last thing they'd do with it is put it in sauce to boil off the alcohol. Jeez oh Pete, how dumb can Americans get? You will not see this in Sicily. Rare to see any meat sauce ("bolognese") either.
But if anyone want to take a tour of Sicily and go on a mission to find "hot and spicy" foods, or "Italian tacos" or street food made with dogs, have at it and report back!
