Miso Butter Halibut Skillet with Shiitake and Bok Choy

A thick halibut fillet in a hot cast iron skillet, basted in melted butter and a spoonful of miso butter until the edges turn golden. Shiitake mushrooms brown beside it and baby bok choy wilts into the buttery pan sauce. This one-pan dinner comes together in about 30 minutes and needs only one skillet to cook and serve.

This miso butter halibut skillet is built around one idea: sear the fish in a generous amount of butter and keep basting it so the flesh cooks gently while the edges turn golden. The shiitake mushrooms go into the pan right alongside the fish, soaking up the same butter and picking up a deep, caramelized flavor. Baby bok choy finishes the dish, wilting in the pan sauce so it stays bright and tender.

Every element cooks in the same skillet, which means the sauce is ready the moment the fish comes out. A small grater of pale yellow cheese, green onions and toasted sesame seeds add the final notes. The result is a complete dinner that feels restaurant-level but needs only one pan and a short list of ingredients.

Ingredients

Why this recipe works

Basting is the key technique here. Spooning foaming butter over the halibut while it sears cooks the top of the fish evenly and gives it a golden crust without drying out the flesh.

The butter also carries seasoning and browning from the pan onto the surface, so each bite tastes rich and well seasoned. Because the fish is thick, this steady heat brings it through to the center before the outside overcooks.

The mushrooms and bok choy work together with the fish. Shiitake release moisture first, then brown in the butter, concentrating their savory, earthy flavor.

Bok choy wilts quickly in the warm sauce, absorbing the miso butter and butter without losing its crisp stems. Cooking everything in one skillet means the pan drippings become a sauce that ties the whole plate together, so nothing needs a separate pot or bowl.

Notes and substitutions

Choose thick, firm halibut fillets of similar size so they cook at the same pace. Pacific halibut is widely sold in American fish counters. If it is not available, cod or sea bass of similar thickness works well, and the basting method stays the same. Ask the fishmonger for skin-on fillets if you want a crisper bottom, but skinless fillets are easier to baste and portion.

A 12-inch cast iron skillet holds heat evenly and gives the fish a deep, crisp sear. It also goes straight from the stove to the table, which keeps the sauce hot.

Miso butter is easy to make at home by beating softened butter with a spoonful of white miso until smooth; it keeps well in the refrigerator. If you prefer a deeper, saltier flavor, use red miso in a smaller amount and taste before adding salt.

• Pacific halibut: cod, sea bass or another thick white fish fillet of similar size
• shiitake mushrooms: cremini mushrooms, sliced
• baby bok choy: spinach or napa cabbage, cut into wide strips
• white miso: red miso in a smaller amount, about half, for a deeper flavor

Equipment

• 12-inch cast iron skillet
• wooden cutting board
• chef's knife
• hand grater
• small mixing bowl
• fish spatula
• spoon for basting