Cozy Up with Icelandic Fiskisúpa

I was meeting with Vilhjálms to discuss Iceland’s fiskisúpa, a cozy soup of flaky white fish suspended in a creamy broth. The first time I tasted it, I was taken by the way the preparation coaxes heartiness and complexity from little more than fish, cream, and some aromatics.

This, Vilhjálms says, is the Icelandic cook’s calling card: the ability to make do when resources are few. For much of the country’s isolated history, those resources were primarily dairy and marine proteins. “If we’re talking about historical Icelandic food, it’s not just that fish was an important part of it,” Vilhjálms said. “It’s that that’s what it was.” 

Modern fiskisúpa recipes have diverged from the oldest recipe Vilhjálms could dig up, a 1791 formula that calls for only fish, cream thickened with wheat, vinegar, lemon, and chopped celery. Today’s cooks might add sweet dried fruit, other seafood, tomato products, or garnishes of chopped chives or a dollop of lightly whipped cream. 

Fiskisúpa’s base is traditionally a stock made from fish bones, but since I planned to use convenient boneless fillets, I’d need to find an alternative. Bottled clam juice and water made a pleasantly briny broth, but I’d need to use my other ingredients to further bolster the soup’s depth.

So, I turned my attention to the aromatics: celery, onions, and leek. Historically, aromatics weren’t often browned in Icelandic recipes. In soups, it wasn’t uncommon to simply boil the aromatics along with the rest of the ingredients. In a nod to this tradition, I tried sweating the aromatics, or softening them in a covered pot over gentle heat, instead of sautéing them. The process took longer, but it presented a couple of perks.

The tender, translucent aromatics wouldn’t disrupt the soup’s brothy texture or muddy its color as sautéed ones would. And they provided extra flavor depth: Gently cooked alliums develop deeper flavor that gets drowned out when they brown but shines in a simple recipe like this.

I added sherry to the Dutch oven for brightness and then poured in the clam juice and water along with a pound of Yukon Gold potato chunks. While it’s more traditional to serve boiled potatoes alongside the soup rather than in it, I loved the creamy texture and deep seasoning they developed as they simmered to tenderness in the broth.

As the potatoes cooked, I stirred tomato paste into a half cup of heavy cream to help distribute the paste in the pot. I withheld the acidic paste until after the potatoes were finished because acid strengthens the pectin in potatoes’ cell walls, impeding softening.

The fish (I chose cod, but any flaky white fish would do) should be the focus of fiskisúpa, and I wanted it to stay in substantial, meaty chunks. So I cut it into large pieces and treated it gently, adding the fish to the pot in a single layer, covering, and stirring only occasionally until the delicate fillets were steamed through.

Topped with chives and served with rye bread, the soup was hearty and nourishing yet bright and light.