Cacio e Pepe Brussels Sprouts

Cacio e pepe is a traditional Roman pasta dish that has the comfort and simplicity of buttered noodles and the complexity of risotto. Although it translates to “cheese and pepper,” in Italian, as a whole, cacio e pepe is more than the sum of its parts: Pecorino Romano cheese and freshly ground black pepper (and sometimes a little butter) are tossed with pasta-cooking water to create a creamy sauce that coats pasta without the need for heavy cream or milk. The dish has become a go-to quick meal on nights when I need something comforting, but don’t feel like spending hours at the stove. Here, I’ve taken the flavors of cacio e pepe as inspiration for a vegetable side, swapping out the pasta for crispy roasted Brussels sprouts. 

Cacio e pepe Brussels sprouts are easy enough to make as part of a weeknight meal, like pantry pasta. But they’re also special enough to serve as a holiday side to your Thanksgiving turkey (or herby roasted turkey legs).

To state the obvious, Brussels sprouts and spaghetti cook very differently. While the cacio e pepe flavor profile in this recipe is reminiscent of the classic pasta, the sauce ingredient lists and technique are not. The inspiration for the sauce in the dish, and the method I finally landed on (after four to five rounds of testing!) come from a Serious Eats article that explains how to turn “bad melters good.” 

According to Serious Eats, the best melters out there are younger, high-moisture cheeses, like mozzarella, while the most difficult are drier, aged cheeses, like Pecorino Romano and Parmesan — two typically used in cacio e pepe sauce. To transform these bad melters, one must add starch (pasta water does this for the traditional dish), which is how a dish of cacio e pepe manages to be smooth and creamy.

In this recipe, the sauce is made as the sprouts are roasting and drizzled on before serving, so I needed a way to create a creamy sauce without the starchy pasta water. My final sauce recipe and method is based on my favorite food science expert J. Kenji López-Alt’s cheese sauce recipe, where he adds cornstarch to milk to create a smooth and gooey sauce. Ingenious!

• Pecorino Romano and Parmesan Cheese: Traditionally, cacio e pepe uses just Pecorino Romano cheese, but I love the combination of the funky, saltier Pecorino with the more mild and familiar Parmesan.
• Freshly ground black pepper: Don’t use the pre-ground stuff for this recipe — you want those spicy, freshly cracked flecks of black pepper for the ultimate zippy flavor here.
• Cornstarch: The starch is crucial to ensure the cheese melts properly and doesn’t clump or break the sauce.
• Whole milk: Although it’s not a traditional cacio e pepe ingredient, some liquid is needed to make a sauce. Milk is richer than plain water, but not too flavorful that it would risk overshadowing the stars of the show (the cheeses and pepper).