Wander away from the throngs of tourists, down a side street off any number of Rome's small piazzas and you'll likely stumble upon a tiny trattoria that serves incredible cacio e pepe ("cheese and pepper" in Italian). But if you're looking for a similar experience closer to home, just walk into Pastaria (7734 Forsyth Boulevard, Clayton; 314-862-6603) for a version that is every bit as authentic -- minus the ancient ruins.
Pastaria's canestri cacio e pepe is a spot-on version of the classic Roman specialty. The dish couldn't be simpler: squat, curved noodles tossed with olive oil, crushed black pepper, Grana Padano and pecorino cheeses. The flavors combine, however, to form a glorious symphony of salt, tang, earth and spice that is so rich it's hard to believe it doesn't contain butter or cream. This grown up mac & cheese is a Roman holiday in a bowl.