For the life of me, I cannot remember where I first tasted the inspiration for this Crispy Cod with Leek Broth and Lemon-Thyme Butter, but I remember exactly how it felt.
It was one of those early spring days in New York where winter hadn’t fully let go. It was still cold, but you could feel the shift coming. And this bowl matched that moment perfectly – light and bright, but still warm enough to take the chill off.
This isn’t a dish that shouts, and I think that’s why it works so well. The broth is clean but layered – chicken stock for body, a little fish sauce for that subtle briny depth, and lemon at the end to keep everything from feeling flat.
That light cornstarch coating on the cod gives you a thin, crisp crust without turning it into a full-on fried situation, and the cayenne adds just enough heat to wake everything up. Then you finish with that lemon-thyme butter, which melts right into the broth and ties the whole thing together.
NOTES:
- LEEK PREP: If you haven’t cooked with leeks before, trim the root and dark green tops. Slice, then rinse well in a bowl of cold water, lifting the leeks out so any grit stays behind.
- MAKE AHEAD: The broth can be made up to 2 days ahead and reheated gently. Cook the fish, make the butter and add the peas just before serving.
- SUBSTITUTIONS: Halibut or haddock work well in place of cod.
A huge thanks to those who tested this recipe: John Donovan, Noelle Hale, Katie Orme, Glenna DiGiacomo, Erin Askew, Teri Lantz, Sarah Hinman
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Crispy Cod with Leek Broth and Lemon-Thyme Butter
Ingredients
For the Leek Broth
- 1 tablespoon unsalted butter
- 1 tablespoon olive oil
- 2 cups thinly sliced leeks (from about 2 medium leeks), well rinsed (See Note)
- 1/2 teaspoon kosher salt
- 2 teaspoons finely grated garlic (about 2 cloves)
- 1/2 cup dry white wine, such as Sauvignon Blanc
- 4 cups low-sodium chicken broth
- 1 tablespoon fish sauce
- 2 fresh thyme sprigs
- 1 tablespoon fresh lemon juice
For the Cod
- 4 (5- to 6-ounce) skinless cod fillets, patted very dry
- 1 teaspoon kosher salt
- 2 tablespoons cornstarch
- 1/2 teaspoon cayenne
- 2 to 3 tablespoons vegetable oil
To Finish
- 1 cup frozen peas (do not thaw)
- 3 tablespoons unsalted butter, cubed
- 1 teaspoon finely grated lemon zest
- 1 teaspoon finely minced fresh thyme
- 1/4 teaspoon kosher salt, plus more to taste
- 2 tablespoons finely chopped chives
- Freshly ground black pepper
Instructions
Make the Leek Broth
- Heat 1 tablespoon unsalted butter and 1 tablespoon olive oil in a medium saucepan over medium heat. Add 2 cups thinly sliced leeks and 1/2 teaspoon kosher salt. Cook, stirring occasionally, until softened and just beginning to turn light golden at the edges, 7 to 9 minutes.
- Add 2 teaspoons finely grated garlic (about 2 cloves) and cook for 30 seconds, until fragrant. Pour in ½ cup dry white wine and simmer until slightly reduced, 2 to 3 minutes.
- Add 4 cups low-sodium chicken broth, 1 tablespoon fish sauce, and 2 fresh thyme sprigs. Bring to a gentle boil, then reduce to a low simmer. Cook for 12 to 14 minutes until the leeks are very tender and the broth is fragrant. Remove both thyme sprigs. Stir in 1 tablespoon fresh lemon juice.
- Now comes the most important step: tasting. The broth should be savory with a subtle, briny depth. If it tastes flat or muted, it almost certainly needs more salt – not enough to taste salty, but enough to make every flavor pop. For more umami richness, add a splash more fish sauce. Adjust until the broth feels vibrant and balanced.
- Reduce heat to low, cover loosely, and keep warm while you cook the fish.
Cook the Fish
- Season 4 pieces boneless, skinless cod fillets on all sides with 1 teaspoon kosher salt.
- On a small plate, mix 2 tablespoons cornstarch and 1/2 teaspoon cayenne pepper. Lightly coat only one side of each fillet, shaking off any excess. This creates a delicate crust while keeping the fish tender, and helps prevent sticking.
- Heat 2 to 3 tablespoons vegetable oil (enough to generously coat the bottom of the pan) in a large nonstick or well-seasoned skillet over medium-high heat until shimmering.
- Place the cod in the pan, coated-side down. Press gently for 10 seconds to ensure full contact. Cook undisturbed for 3 to 4 minutes, until deeply golden and the fish releases easily from the pan.
- Flip and cook for another 2 to 3 minutes. The fish is done when it flakes easily with a fork and is opaque around the edges with a slightly translucent center.
- Transfer to a plate and loosely tent with foil.
Finish the Dish
- Reduce heat to low. Add 3 tablespoons cubed unsalted butter to the same pan and let it melt gently, scraping up any golden bits from the bottom. Avoid letting the butter brown.
- Once melted, remove from heat and stir in 1 teaspoon finely grated lemon zest, 1 teaspoon finely minced fresh thyme, and 1/4 teaspoon kosher salt.
- Add the 1 cup frozen peas to the broth and simmer for 2 to 3 minutes, until bright green and tender. Taste and adjust seasoning if needed.
- Ladle the broth, leeks, and peas into shallow, wide bowls (about 1 to 1 1/4 cups per serving). Place a cod fillet in each bowl.
- Spoon about 1 tablespoon of the lemon–thyme butter over each fillet. Top with a sprinkle of chives and a pinch of black pepper. Serve immediately.
