How Commonwealth Makes Those Duck Fat Fries

Nookie Postal's twice-cooked steak fries have become a savory staple for breakfast, lunch, and dinner.

In our second annual Starch Madness bracket, you voted for your favorite carb dishes around Boston. Last year’s runner-up, Commonwealth, once again had a good showing, dominating the Potato Conference and defeating 2015 Starch Madness winner, Shojo. Read more about Commonwealth’s duck fat fries below, and check out the full results of Starch Madness 2016.


All photos by Steve ‘Nookie’ Postal Provided

Sometimes the simplest dishes are the most alluring. Take for instance a perfectly ripe tomato drizzled in extra virgin olive oil, fall-off-the-bone pork ribs, or oysters on the half shell. At their peak, they easily eclipse finicky preparations like Baked Alaska or boueuf bourguignon (sorry Julia!). Commonwealth chef Nookie Postal’s duck fat fries fall into that same impeccable, but streamlined class.

Steak-cut Russets pre-marinated in duck fat and salt, they’re simply baked, then fried in a bath of canola oil—a classic twice-cook technique that leaves them consistently crisp on the outside, but pillowy soft in the middle. It’s a feat that’s hard to replicate on a mass scale, which is why it took Postal so long to nail the recipe.


“At Fenway we made McDonald’s-style home-cut fries. It was this huge process where we cut them and soaked them and steamed them and double-fried them and froze them. It was way too much,” Postal says. “But I knew I wanted to do some kind of hand-cut fry, so we settled on the steak fry. I love steak fries, but they have a tendency to get soggy. I used to go to [R.F.] O’Sullivan’s in Somerville all the time and towards the end of the meal, the fries would always be soggy, which I hate! To make them super crispy on the outside, but fluffy in the middle, is extremely hard to do.”

Served with sandwiches at lunch, as home fries on Commonwealth’s weekend brunch menu, and as a popular side during dinner service, Postal’s ubiquitous fries have become a ballast point for the entire restaurant. Now, Postal and his staff are cutting and basting almost 100 pounds of potatoes every day. As Postal himself admits, “That’s a lot of damn fries.”

To make them even more enticing, the chef has a secret duck-based condiment you can only ask for at night: a whipped duck fat aioli which Postal makes with emulsified egg yolks, canola, duck fat, and Commonwealth’s fiery, house-made hot sauce. So, yeah, Postal has not only conquered the precarious potato, but surpassed his McDonald’s-style predecessor at Fenway.