Cod with tomato butter
Braised Cod with Tomato Butter, Fennel Salsa Verde, and Roasted Baby Potatoes
A Mediterranean composed plate — buttery cod, tomato-and-garlic compound butter, sliced avocado, herb-forward fennel salsa, and crispy roasted potatoes
Serves 4 · 35 min active · 1 hr 15 min total · year-round (peak winter–spring cod) · early evening
Ingredients
Roasted baby potatoes
1 ½ lb baby potatoes (mixed colors — purple, red, yellow), halved
3 tbsp extra virgin olive oil
1 tsp sea salt
½ tsp freshly ground black pepper
4 sprigs fresh thyme
Tomato butter
4 tbsp grass-fed butter, divided
2 tbsp extra virgin olive oil
4 garlic cloves, finely minced
2 cups cherry tomatoes (mixed colors), halved
pinch crushed red pepper flakes (optional)
pinch sea salt and freshly ground black pepper
1 tbsp fresh basil, chopped
Cod
4 cod fillets (6 oz each), wild-caught
1 tsp sea salt
½ tsp freshly ground black pepper
2 tbsp extra virgin olive oil
3 tbsp grass-fed butter
2 tbsp fresh lemon juice (juice of 1 lemon)
Fennel salsa verde
1 small fennel bulb, fronds reserved, bulb finely diced
3 tbsp extra virgin olive oil, divided
3 garlic cloves, finely minced
1 cup fresh flat-leaf parsley, finely chopped
1 tbsp fresh rosemary, finely chopped
1 tbsp anchovy paste (or 4 oil-packed anchovy fillets, finely minced)
2 tbsp red wine vinegar
¼ tsp sea salt
¼ tsp freshly ground black pepper
2 tbsp reserved fennel fronds, chopped
To assemble
1 ripe avocado, halved, pitted, sliced
additional fresh basil leaves
additional fresh parsley
lemon wedges, for serving
Optional finishing
2 tbsp grated raw Parmigiano-Reggiano (for the potatoes)
pinch flaky sea salt
Method
Roast the baby potatoes. Preheat the oven to 425°F (220°C).
Toss the halved potatoes with olive oil, salt, and pepper on a parchment-lined baking sheet. Tuck the thyme sprigs in among the potatoes.
Roast 30–35 minutes, turning halfway through, until tender inside and crispy at the edges.
Make the fennel salsa verde. While the potatoes roast, heat 1 tbsp olive oil in a small skillet over medium heat. Add the diced fennel bulb. Cook 8–10 minutes, stirring occasionally, until softened and lightly caramelized.
Add the garlic. Cook 1 minute more. Remove from heat.
Transfer the fennel-garlic mixture to a small bowl. Add the chopped parsley, rosemary, anchovy paste, red wine vinegar, remaining 2 tbsp olive oil, salt, and pepper. Stir to combine.
Fold in the chopped fennel fronds. Taste and adjust seasoning.
Make the tomato butter. In a large skillet over medium heat, melt 2 tbsp butter with the olive oil. Add the minced garlic and cook 1 minute (don't brown).
Add the halved cherry tomatoes, red pepper flakes (if using), salt, and pepper. Cook 5–7 minutes, stirring occasionally, until the tomatoes soften and burst slightly, releasing their juice.
Add the remaining 2 tbsp butter. Swirl until melted and emulsified into a glossy sauce.
Stir in the chopped basil. Remove from heat. Keep warm.
Cook the cod. Pat the cod fillets very dry with paper towels (essential for proper searing). Season both sides generously with salt and pepper.
Heat 2 tbsp olive oil in a large heavy skillet (cast iron or stainless) over medium-high heat until shimmering.
Add the cod fillets, skin-side down (or what was the skin side). Cook 3–4 minutes without moving — a deep golden crust should form.
Flip carefully with two spatulas (cod is delicate). Add the 3 tbsp butter to the pan. As the butter melts and foams, tilt the pan and spoon the foaming butter over the cod, basting continuously.
Add the lemon juice. Cook 1–2 minutes more, until the cod flakes easily with a fork (internal temperature 140°F).
Plate. Spoon a portion of fennel salsa verde across each of 4 plates.
Place a portion of roasted potatoes alongside.
Place a cod fillet next to the potatoes.
Spoon the tomato butter over and around the cod, letting it pool slightly on the plate.
Fan the avocado slices alongside. Spoon a small amount of tomato butter over the avocado.
Finish. Optional Parmigiano grated over the potatoes; flaky sea salt across everything; additional fresh basil and parsley scattered as garnish.
Serve with lemon wedges alongside.
Optional addition: Wilted spinach with garlic. Heat 2 tbsp grass-fed butter in a large skillet over medium heat. Add 3 thinly sliced garlic cloves and cook 1 minute. Add 1 lb fresh spinach (in batches if needed). Cook 2–3 minutes, tossing, until just wilted. Season with salt and a squeeze of lemon. Plate alongside the cod.
Nourishment Notes
Cod is one of the foundational fish of European and North American coastal cookery — the cold-water fishery off Newfoundland, Iceland, and Norway has supplied cod to European tables for over 500 years, and the fish was substantial enough nutritionally to support entire economies (medieval Hanseatic League trade routes were largely built on dried-and-salted cod). Today's wild-caught Pacific and Atlantic cod (look for Marine Stewardship Council certification or Monterey Bay Aquarium "Best Choice" rating) provides high-quality protein, substantial vitamin B12, selenium, and the omega-3 fatty acids EPA and DHA — though cod is leaner than salmon or sardines. Avoid Atlantic cod from depleted stocks; Pacific cod and Icelandic cod are typically the more sustainable options.
The pan-sear-then-butter-baste technique on the cod is borrowed from classical French cuisine bourgeoise — searing first for the golden crust, then finishing with butter, lemon, and continual basting. The continuous basting with foaming butter is the structural detail that distinguishes a good cod fillet from a great one: each spoonful of hot butter that lands on the fish contributes flavor, moisture, and the slight nutty depth of beurre noisette. The same approach drives French poisson meunière, English fish and brown butter, and Italian pesce al burro. Cod's mild, slightly sweet flavor takes especially well to this technique because the butter doesn't compete with strong fish flavor.
Anchovy paste in the fennel salsa verde is the structural element that pulls this sauce into Italian-Provençal flavor territory and amplifies its complexity. Anchovies contribute concentrated umami and salt — the same compounds that make Italian bagna cauda, French tapenade, and Spanish anchoas en aceite foundational across Mediterranean cookery. Used at 1 tablespoon, the anchovy paste disappears into the herbs but leaves a deep savory note that the sauce would otherwise lack. Vegetarians can substitute 1 tablespoon white miso or 1 teaspoon nutritional yeast for similar umami contribution without the fish.
The composed-plate architecture of cod + tomato butter + fennel salsa + potatoes + avocado is structurally borrowed from modern Mediterranean restaurant cooking — particularly the chef-driven Provençal and Italian Riviera traditions where multiple sauces and components occupy different positions on the plate. Each element serves a distinct function: the tomato butter is rich, glossy, and warm; the fennel salsa is bright, herbaceous, and slightly acidic; the avocado is creamy and cooling; the potatoes are starchy and substantial. Eating bites that combine multiple elements produces a more complex flavor experience than any single component alone.
Storage: Best eaten same day. Tomato butter alone keeps refrigerated 3 days. Fennel salsa verde keeps refrigerated 4 days. Roasted potatoes keep refrigerated 3 days; reheat at 400°F for 8 minutes to recrisp. Cooked cod doesn't reheat well — eat the day it's cooked.