Miso Butter Seared Halibut with Mushrooms and Bok Choy

A thick halibut fillet with a golden crust, glazed in white miso and ginger butter, is a dinner that looks restaurant-quality and comes together in one skillet. Shiitake and bok choy take on the glaze, and the whole plate is ready in about 25 minutes. It is simple to make on a weeknight and still feels special enough to serve to guests.

This dish brings together a firm, mild fish and a savory glaze built in a single cast iron skillet. Fresh ginger is grated straight over the cutting board so its juice and pulp fall where you need them.

Butter melts with the ginger and garlic, the halibut sears undisturbed, and then white miso, soy sauce and a splash of mirin create a glossy coating on the fish.

Shiitake mushrooms and baby bok choy cook in the same pan, soaking up the glaze as the fish rests on top. Finish with scallions and toasted sesame seeds for a bright, savory plate that needs nothing else on the side.

Ingredients

Why this recipe works

Searing the halibut in butter gives it a golden crust while the inside stays moist and tender. Starting the fish skin-side-free and undisturbed lets the surface form a crust that releases cleanly from the pan. Basting with the foaming garlic butter carries heat over the top of the fillet, so the thick centre cooks through as the edges brown.

Miso and soy are added to the pan at the end, after the fish has seared, so their sugars caramelize instead of burning. White miso is mild and slightly sweet, which balances the salt of the soy sauce. Mirin or water thins the mixture so it spreads evenly and reduces into a glaze that clings to the mushrooms and fish.

Notes and substitutions

Choose halibut fillets that are thick and even, about 1 inch at the centre, so the outside browns before the middle overcooks.

A 12-inch cast iron skillet holds the fish, the mushrooms and the bok choy in one layer and distributes heat evenly for a strong sear. A fine box grater makes the ginger into a pulp that melts into the butter, giving more flavor than chopped pieces would.

Mirin adds gentle sweetness and gloss, and you can replace it with water if you prefer a less sweet glaze. White miso is the classic choice here; yellow miso works but tastes stronger and saltier, so reduce the soy sauce slightly.

Remember that both miso and soy sauce contain soy, and that soy sauce and mirin contain gluten or sulphites, so check labels if you are cooking for guests with allergies. Toast the sesame seeds in a dry pan for a minute for the best aroma.

• halibut: cod or sea bass fillets of similar thickness, cooked to the same 145°F (63°C) internal temperature
• mirin: water, or a splash of dry sherry for a deeper sweetness
• baby bok choy: spinach or napa cabbage wedges, added at the same stage
• white miso: yellow miso, which gives a slightly stronger, saltier glaze

Equipment

• 12-inch cast iron skillet
• fine box grater
• cutting board
• chef's knife
• fish spatula or tongs
• small bowl for whisking