A question about a recipe: Spaghetti with cherry tomatoes and pecorino cheese. what is peperoncino or chile de arbol?

Hi there, happy you liked it. As they have already mentioned, chile de arbol and peperoncino are two dried chiles, the first Mexican, the second typical of Italy. They are not exactly interchangeable, because the chile de arbol is 30 times hotter than the peperoncino (have a look here for the heat scale of chiles: http://www.tuscanfoodie.com/2010/11/hot-as-tuscan-foodie-my-discovery-of.html). As mentioned in the recipe, if you don't like things to be too hot, and you are using chile de arbol, you may have to cut down the quantity.

Thanks everyone! I ended up using the chili de arbol. this is an excellent, light pasta dish. I am now drinking the rest of the required white wine! Perfect Sunday night dish

Slightly incorrect on the pepperoncino, but not completely. In Italian it can refer to either a dried or pickled small hot pepper. But the pickled style would not be interchangeable with arbol as substitute.

Lorogoldsby is spot on. The difference between the two is that a chile de arbol is a dried chile, while a peperoncino is a fresh pickled pepper. They're pretty equal in their heat. Given a choice, I'd go with the chile de arbol.

I think Tuscanfoodie is calling for a little bit of heat here--the chili de arbol can be found in the spice aisle either ground or whole...and you might be familiar with the little greenish yellow peppers often served with pizzas--sometimes called peppercini here in the states?