Learn Hardcore Italian: Il pollo cotto al forno è buono.

In Italian, when you talk about food in a general or uncountable sense, you normally include the definite article. So Il pollo here means “chicken” in general. Dropping il would make it sound like you’re referring to one specific chicken, not the dish as a category.

What is cotto in this sentence?

Cotto is the past participle of the verb cuocere (“to cook”), used here as an adjective meaning “cooked.” So pollo cotto literally means “cooked chicken.”

Why does the adjective cotto come after the noun pollo, instead of before it?

In Italian, most descriptive adjectives—and especially past participles used adjectivally—follow the noun they modify. Hence pollo cotto, not cotto pollo.

What does al forno mean, and why not use nel forno?

Al forno literally means “to the oven,” but idiomatically it means “baked.” Italian cooking phrases use a/allo/alla/al + [cooking place or tool] to indicate method:

al forno = baked
alla griglia = grilled
in padella = fried
Saying nel forno would emphasize location (“inside the oven”) rather than the cooking method, so it’s not the usual choice.