Black Cod with Tomato-Fennel Sauce, Smashed Potatoes, and Whole-Roasted Romanesco

Tomato-Fennel Sauce

Slowly softening the fennel develops sweetness that balances the tomatoes. Keeping the sauce slightly loose lets it gently cook the fish and soak into the potatoes.

Ingredients

• 2 tablespoons extra-virgin olive oil
• 1 large fennel bulb, cored and thinly sliced; reserve a few fronds
• 3 cloves garlic, thinly sliced
• 1 28-ounce can whole peeled tomatoes with their juices, crushed by hand
• 1/2 cup water
• 1/2 teaspoon kosher salt, plus more to taste
• 1/4 teaspoon freshly ground black pepper
• 1–2 teaspoons fresh lemon juice, to taste

Instructions

1. Warm the olive oil in a wide, deep skillet over medium-low heat. Add the fennel and salt; cook for 10–12 minutes, stirring occasionally, until softened and translucent without substantial browning.
2. Add the garlic and cook for 1 minute. Add the tomatoes, their juices, water, and pepper.
3. Simmer uncovered for 18–20 minutes, stirring occasionally, until the fennel is tender and the sauce is cohesive but still spoonable. Add a splash of water if it becomes thick enough to mound.
4. Taste and adjust the salt. Add lemon juice only as needed to brighten the tomatoes. Keep the sauce in the skillet for cooking the cod.

Notes

• If the tomatoes are especially sharp, simmer a little longer with the fennel before adding any lemon.

Gently Poached Black Cod

Black cod's rich flesh stays succulent in a barely simmering sauce. Cooking it in large portions before gently separating the flakes preserves its delicate texture.

Ingredients

• 1 1/2 pounds black cod (sablefish), skinless and pin-boned, cut into 4 portions
• 1/2 teaspoon kosher salt
• 1 batch prepared tomato-fennel sauce

Instructions

1. Pat the fish dry and season lightly with salt.
2. Bring the tomato-fennel sauce to a very gentle simmer in its wide skillet. Nestle the fish into the sauce in a single layer and spoon some sauce over each piece.
3. Cover and cook over low heat for 10–14 minutes, depending on thickness. Keep the sauce at a bare simmer rather than a boil.
4. Check the thickest portion with an instant-read thermometer; cook to 145°F. The flesh should be opaque and separate into moist, broad flakes.
5. Lift the fish with a wide spatula. Leave portions intact or gently separate them into a few large pieces for serving, without stirring them through the sauce.

Notes

• Black cod is delicate: use a spatula rather than tongs, and avoid repeatedly turning it.

Rustic Smashed Potatoes

Skin-on potatoes provide an earthy, textured base for the soft fish. Butter rounds out the tomatoes without making the potatoes overly rich or smooth.

Ingredients

• 1 3/4 pounds Yukon Gold potatoes, skins on, cut into roughly 2-inch pieces
• 3 tablespoons unsalted butter
• 2 teaspoons kosher salt for the cooking water, plus more to taste
• 1/4 teaspoon freshly ground black pepper

Instructions

1. Put the potatoes in a saucepan, cover with cold water by 1 inch, and add the salt. Bring to a boil, then simmer for 18–25 minutes, until a knife slides through easily.
2. Reserve 1/2 cup of cooking water, then drain. Return the potatoes to the warm pan over low heat for 1 minute to let excess moisture evaporate.
3. Remove from the heat, add the butter, and crush roughly with a potato masher or sturdy fork, leaving some chunks and visible skins.
4. Fold in 2–4 tablespoons of reserved cooking water as needed to keep the potatoes soft but not loose. Season with pepper and additional salt to taste. Cover and keep warm.

Whole-Roasted Romanesco

An initial covered roast helps the dense core soften before the exposed tips brown. Leaving tender leaves attached adds the crisp, curled edges that contrast with the fish and potatoes.

Ingredients

• 1 large head romanesco, about 2 pounds
• 3 tablespoons extra-virgin olive oil
• 3/4 teaspoon kosher salt
• 1/4 teaspoon freshly ground black pepper
• 1/4 cup water
• 2 teaspoons fresh lemon juice

Instructions

1. Heat the oven to 425°F. Trim the tough outer leaves and stem base so the romanesco stands upright, retaining tender inner leaves. Cut a shallow cross into the exposed stem base without breaking apart the head.
2. Set the romanesco in a snug baking dish. Rub with the olive oil, working some between the florets, and season with salt and pepper.
3. Pour the water into the bottom of the dish and cover tightly with foil. Roast for 25–30 minutes.
4. Uncover carefully and spoon the pan juices over the head. Roast for another 25–35 minutes, until a skewer enters the core easily and the tips and leaves are deeply browned. Loosely shield individual leaves if they begin to burn.
5. Rest for 5 minutes, drizzle with lemon juice, and cut through the stem into four wedges.

Notes

• A very large or dense head may need another 10–15 minutes covered before browning; tenderness at the core is the deciding cue.

Overall Timing / Workflow

The romanesco takes longest and can rest briefly. Finishing the fish last keeps it tender while the potatoes and sauce hold well.

Instructions

1. 0:00 — Heat the oven to 425°F, prepare the romanesco, and begin its covered roast.
2. 0:10 — Slice the fennel and garlic and start the tomato-fennel sauce.
3. 0:25 — Uncover the romanesco when ready. Start the potatoes in cold salted water.
4. 0:45 — Finish and season the sauce. Drain and smash the potatoes once tender; keep covered and warm.
5. 0:50 — Check the romanesco's core. When it is nearly tender, begin poaching the cod in the sauce.
6. 1:05 onward — Rest and quarter the romanesco, check the fish temperature, and plate immediately. Allow additional oven time if the romanesco is particularly dense.

Plating

Placing the fish and sauce over the potatoes catches the juices, while keeping the romanesco alongside preserves its browned edges.

Ingredients

• 1 tablespoon reserved fennel fronds, roughly chopped

Instructions

1. Spoon a generous mound of smashed potatoes slightly off-center in each warm shallow bowl.
2. Set the cod over the potatoes and spoon tomato-fennel sauce over and around it, leaving some white fish and potatoes visible.
3. Place a wedge of romanesco alongside, browned tips and leaves facing upward. Finish the fish with a few fennel fronds.

Leftover Path

Storing the vegetables separately keeps their flavors distinct, while sauce protects the fish from drying out during reheating.

Instructions

1. Refrigerate within 2 hours, keeping the fish with its sauce and the potatoes and romanesco in separate airtight containers. Use the fish within 2 days and the vegetables within 3–4 days.
2. Reheat fish and sauce gently in a covered skillet with a splash of water, without boiling, until the fish reaches 165°F.
3. Warm the potatoes in a covered saucepan with a little water, stirring occasionally. Reheat romanesco in a 400°F oven for 10–15 minutes to restore some browned texture.
4. For a different second meal, loosen the leftover tomato-fennel sauce with water into a light stew, add chunks of potato and romanesco, and gently warm the flaked fish in it at the end.