Brown Butter Cod and Potatoes
If it still feels like winter where you are, turn to cod and butter
It’s supposedly April, and yet as I write this, the weather in New York is as damp and blustery as February in Seattle. I’m eagerly awaiting a spring bounty at the farmer’s market — asparagus, peas, ramps, etc. — but that seems to be further and further away as the unseasonable cold drags on. No matter: as you wait for some actual green at the greenmarket, you can make this warming, hearty cod, cooked in brown butter and set on a pillow of potato purée. It sports a well-seared crust with lots of big flavor, and even though the spring weather is nowhere to be found, a bright salad of fennel, celery, and Castelvetrano olives offers some much-needed green amidst all the butter.
Cod is a great fish that is often subject to abuse in home kitchens — limply-baked sheet pan recipes and frozen fish sticks come to mind. But you don’t have to resort to a restaurant for properly cooked cod; you don’t even need to expend much effort for it to be just as stunning as swordfish or tuna. This super-easy sear-and-baste method is the way to go.
Like the crisp-skinned arctic char recipe I posted a few weeks back, you’ll ideally need a well-seasoned carbon steel pan for this. Should you not have one, you can use a well-oiled stainless steel pan — just don’t bother with a non-stick. And if you’re worried about it sticking, I always recommend testing a small piece first.
Brown Butter Cod, Potato Purée, and Fennel Salad
Makes 2 servings
1 pound skinless cod filet, cut into two equal-sized pieces
1.5 sticks of butter, preferably cultured
4 Yukon gold potatoes
1 cup of milk
1 bulb fennel
3-4 celery stalks, plus a handful of celery leaves
Handful of Castelvetrano olives, roughly torn in half
Handful of parsley leaves, roughly chopped
1 tablespoon of capers
Champagne or red wine vinegar
Vegetable or canola oil
Extra virgin olive oil
Cracked black peppercorns
Start by preparing the potato purée. Peel the potatoes completely and cut them into chunks; place them in a saucepan filled with water and bring to a boil. Once boiling, salt the water generously.
Boil for 20-30 minutes until they are completely soft; you should be able to easily pierce them with a fork. Drain the water from the pot and cover with a lid to let them steam for 5 minutes. Take about 3/4ths of a stick of butter and cut it into very small chunks.
Using a ricer or a food mill, process the potatoes into a bowl; they must still be hot while doing so. Once the potatoes have been riced, put them back into the saucepan with the cubed butter. Set it over low heat. Add a cup of milk and mix well with a fork. The consistency should be light, airy, and completely smooth (no lumps). Salt to taste. Cover and set aside.
Prepare the fennel salad. Remove the top of the fennel bulb; cut the bulb vertically in half. Using a mandoline, thinly shave the fennel into a large bowl. Squeeze a slice of lemon over the fennel to prevent it from oxidizing.
Using the mandoline, shave the celery horizontally (they way you would normally cut a celery stalk into slices, but with the mandoline; you can also just cut with a knife). Add the celery leaves to the bowl.
Add parsley, olives and capers to the bowl. Don’t add salt or oil until just before serving. Set aside.
Remove the cod from the fridge and thoroughly pat dry.
Set a carbon steel or stainless steel pan over very high heat. Add 2-2.5 tablespoons of oil to the pan.
Once the pan is smoking hot, liberally salt the cod on both sides. Add it to the pan and immediately press down with a fish spatula. (Now is also a good time to put the potatoes on low heat.)
Let it sear on this side, on high heat, for about five minutes, occasionally pressing it. At the 5 minute mark, start to check and see if it is still sticking to the pan; you should be seeing browned edges at this point. Turn down the heat to medium. Squeeze a lemon slice over the fish to help it separate from the pan. Add half a stick of butter to the pan and begin basting the top of the fish.
Baste the exposed top of the fish for 3-4 minutes. At this point, the fish should be ready to flip; using the fish spatula, gently separate it from the pan (you don’t want to accidentally rip off any of the crust), and flip.
Baste the seared side for another 2-3 minutes. At this point, the butter should be golden brown with a nutty aroma (it should not be black or smell bitter/acrid; you’ll want to manage the heat levels to prevent this). If you have a cake tester handy, you can use this to test for doneness; the cake tester should be warm to the touch after being inserted into the middle of the cod. Remove the fish from the pan.
Place a dollop of potato purée on the plate. (Tip: I like to take the spoon I used to baste the fish and mix the potatoes with it before plating. It imparts some of the brown butter.) Place your fish on top of the potatoes.
At the last moment, douse your fennel salad with a generous amount of olive oil, salt, and pepper, as well as a sprinkle of vinegar. Plate the salad so that it is next to the fish, but overflowing a bit on top.