It's Christmas Eve in Slovakia, and there's a carp swimming in the tub.
The family is here, the tree is finally up and the scaly little guy is alive and well in the bath, biding his time until he's breaded and fried for a traditional supper of plate-size wafers topped with symbolic slivers of garlic (for health), walnuts (for beauty) and a drizzle of honey (for a sweet temperament), accompanied by potato salad and a spicy, meaty sauerkraut soup known as kapustnica (see the recipe).
The soup is a must-have on this Eve, but funny enough, it's popular year-round in Slovakia. Why? We're not sure. But we're thinking it's because of the paprika- and serrano-spiced broth that makes your nose a tiny bit runny, the crunchy slices of sauerkraut soaking up that juice, the nubs of peppery sausage and handfuls of dried sour cherries and soft onions for a little sweetness, all to make a smoky, briny soup that would be pretty darn delicious every day of the year.
For this Christmas miracle of a discovery, we thank Nick Balla and Cortney Burns, the creative but Old World-minded chefs at Bar Tartine in San Francisco. The duo dropped by our Test Kitchen to show us how to make the soup, one of several Eastern European-inspired recipes included in their new cookbook, Bar Tartine: Techniques and Recipes (Chronicle, $40).
"I remember you making that early on," Burns says to Balla. "It's one of the first things he ever made for me, a huge rondo of kapustnica, and he threw lentils in at the end. There were about six gallons of it."
"It's just the perfect day-off food," Balla counters. "The flavors are so addictive, the agrodolce of sweet and sour. It's always satisfying."
Balla's love of kapustnica began as a teen growing up in Hungary. He spent one Christmas in Slovakia at three different homes of his father's friends and slurped up three versions of his soon-to-be favorite soup. Now he passes on the tradition to us.
In our kitchen, Balla and Burns set to work on their version: They lay a counter-size cutting board on the table; Balla takes to chopping the vegetables and Burns the sausage, which she pops into her mouth every now and then.
"My dad makes it different every time," Balla says. "Sometimes, the right sausage isn't available, so he'll make it with smoked chicken or a ham hock. Other times, he'll drop in prunes and apricots or extra onions."
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"It's very much indicative of how we cook," Burns adds. "We think of our recipes as templates for people, and we hope that they'll insert their own likes and unique availability to this."
At their restaurant, Balla and Burns smoke and grind chiles—thousands of pounds at a time—to make their own paprika and fill every nook and cranny of the restaurant with pickled Brussels sprouts, other fermented foods and farmers' cheeses. There, they rely on these old-school techniques for new-school dishes they're so beloved for, like the ever-popular smoked potatoes with ramp mayo.
With kapustnica, though, there's innovation in every bowl, depending on what you find in your fridge.
"It's super forgiving, so you can put your favorite stuff in there and tailor it to your taste," Balla says. "You just cut up everything, throw it in the pot, you watch half of a movie, turn it off and eat it during the second half of the movie."
"Then eat ice cream," Burns encourages.