I love butter-poaching fish. It’s the gentle, luxurious cousin to steaming. Butter enhances the rich flavor that already exists in a meaty white fish like halibut, and because the fish is removed from the clarified butter before serving, it never feels greasy or excessive.
For this recipe, ask for the center cut of the halibut, from the fattest piece in the case (if you don’t see one, ask the fishmonger if he or she has more in the back). Your fish must be evenly thick so all of the pieces cook at the same rate. Use the smallest pot that accommodates all four halibut pieces without crowding but that will allow the fish to be fully submerged in the butter.
- Yield: 4 Servings
- 2 pounds butter
- 2 teaspoons salt
- 1½ pounds center-cut halibut fillet, skin off, split into 4 uniform pieces (about 5 ounces each)
- Preheat the oven to 350°F. In a 4-quart ovenproof saucepan, heat the butter over medium heat until melted and starting to simmer, 5 to 7 minutes. Once white foam begins to form on the surface of the butter, use a small ladle or shallow spoon to gently skim the foam and discard it. Turn down the heat to medium-low and continue the gentle bubbling, removing any foam every 2 to 3 minutes, until no more foam appears. This may take up to 20 minutes.
- Once the surface of the butter looks clear and glassy (you may have a few small pieces of milk solids on the bottom; this is okay as they’ll be strained out), set a fine-mesh strainer over a bowl and line the strainer with a double layer of cheesecloth. Pour the butter through the strainer and discard the cheesecloth. Wash and dry the saucepan.
- Return the clarified butter to the saucepan while the butter is still warm. Add the salt and stir well. Taste the butter; it should be nicely seasoned. Gently add all of the halibut to the saucepan; the fish must be completely covered with butter. If it is not completely submerged, try using a slightly smaller pan, or top off with a tiny bit of extra-virgin olive oil. Place the pan, uncovered, in the oven and set a timer for 8 minutes.
- Remove the saucepan from the oven. Using a slotted spoon or fish spatula, take the smallest fillet out of the butter. Press on it gently, and at one of the natural breaks of the flesh, pull the flesh back slightly and peek inside to make sure the meat is opaque almost entirely through. There should still be a very slight translucence just at the center. Thicker pieces of halibut may take up to 10 minutes to cook.
- To serve with Spring Pea–Mint Relish and Beurre Blanc as shown (see photo), make the relish up to 6 hours and the Beurre Blanc up to 1 hour before serving. Do not attempt to poach the halibut and make the Beurre Blanc at the same time, as they both require your full attention. Keep the Beurre Blanc warm in a thermos until you’re ready to serve. Poach the halibut immediately before serving.
- Remove the halibut from the butter and plate each piece individually. Spoon about 2 tablespoons of Beurre Blanc on top of each portion of halibut and top with an equal amount of room-temperature relish. Garnish with pea tendrils, torn pieces of mint, or edible flowers.