It's time for another round of The Food Lab. Got a suggestion for an upcoming topic? Email Kenji here, and he'll do his best to answer your queries in a future post. Become a fan of The Food Lab on Facebook or follow it on Twitter for play-by-plays on future kitchen tests and recipe experiments.
Just like this recipe, this installment of The Food Lab is going to be short and sweet (or should I say short and savory?).
Fall weather tends to have one of two effects on me. On a good day, it makes me want to get into the kitchen and spend hours cooking a single dish. A stew, or a slow roasted pumpkin soup, or a batch of carnitas, maybe. Something that'll fill the house with fall-like smells of roasting meat and hearty vegetables.
Other times, it makes me feel lazy, where I want to do nothing more than sit on the couch, play some video games, and not have to worry about what's for lunch. That's when recipes like this come in handy. Five ingredients (and really, you can get away with four), one pot, 20 minutes, and pretty much zero effort, and in return you get a ton of flavor.
The first time I tasted the precursor to this dish was a few weeks ago on a trip to Alaska where I was joined by Jessie Ziff-Cool. If you don't know her and her food (you should), might be described as Alice Waters' cooler, more relaxed and groovy counterpart.
One night during our trip, she popped into the kitchen and came out a little while later with this amazing salad of cooked fingerling potatoes tossed with smoked salmon and crème fraîche. So simple, and wicked tasty. It's the same dish that she serves at her restaurant Flea Street in Menlo Park, though there she gussies it up with truffles and the like.
This recipe is an even simpler version, though, as with all simple foods, attention to detail is important! Here's how we make it.
Now is the time to get great fingerling and new potatoes. I like to use a waxy red-skinned or creamy yellow-skinned variety for this, as they take on a firmer, creamier texture when they cook.
There are two keys to cooking potatoes. First, start them in cold water and bring it to a boil. This helps them cook more evenly from the outside in, preventing the outer edges from overcooking and getting water-logged and mushy before the centers have a chance to soften fully. The second is to cook them in well-salted water. Even with their skins intact, potatoes have a relatively porous structure that allows them to take on seasoning from the water internally as they cook. Take a look at this image below, of a chunk of potato cooked in water dyed green at various stages. The green coloring represents the penetration of liquid and seasoning into the potato as it cooks:
As you can see, potatoes cooked in salted water have the most even seasoning, while those seasoned after cooling even briefly barely pick up any salt at all.
I use lots of salt in my water—about a quarter cup of kosher salt (or two tablespoons of table salt) per quart of water. Famous chefs say the water should taste like salty sea water. If your mouth is not a great barometer for salinity, that's about as salty as, say, a tear or a Chick-Fil-A sandwich. Slicing the potatoes after cooking them will give you a slightly more even cook, but in cases like this, convenience trumps the slight textural advantage, so I just slice them up while they're still cool, raw, and firm.
Here's the real trick to this recipe. While it is a potato and smoked salmon salad, the salmon is really more of a flavoring agent than a main component. In fact, I'd consider it to be part of the dressing more than anything. Salmon—and cured salmon in particular—contains two important compounds: glutamic acid and inosinic acid. These two molecules act in conjunction to make things taste more savory, more meaty in your mouth. It's what gives this dish its rich, satisfying flavor and what elevates it from being a mere side salad to the King of Side Salads, or even the Respectable Middle Class Worker of Main Courses.
The smoke from the salmon only enhances this effect. Biting into a hunk of creamy, robust potato with a hint of smoke satisfies a very primal urge in my belly. I could eat this salad for lunch and not feel like I was missing anything.
What's really great is that there's no need to shell out for the super fancy hand-sliced stuff here. If you've got a deli or supermarket nearby that sells smoked salmon ends and scraps, this is the perfect place to use them since the pieces get chopped up finely. Leftover slices from brunch also work well.
At Fresh Street, Chef Cool uses crème fraîche, a.k.a. fancy-pants sour cream. It's pretty widely available these days, so if you have it, use it. If you don't have it, you have a couple of options. You can either make some yourself using heavy cream and buttermilk (the process is ridiculously simple, though it takes about a day), or just substitute. I tried making this dish with a few different dairy options. Quark and regular yogurt both broke and curdled a bit when I tossed the salad, but regular sour cream and Greek yogurt both held up just fine. I'd give the sour cream a slight advantage here for its richer texture.
Aside from proper seasoning with salt and pepper (I use plenty of pepper—potatoes love pepper), the only other ingredient for the dressing is some lemon juice to brighten it up and a sprinkling of herbs. Parsley works well, as do chives, tarragon, or even some sliced scallions.
And now we dive into the deep science of potatoes and dressing...just kidding. That's it. No tough lessons today, just a super simple, super delicious recipe. There is, however a homework assignment. I think you know what it is. I expect a full report in the morning.