Technically, fish can last up to half a year in a freezer, but their quality starts to slide after the first month. Braising those longer-term residents of your deep freeze in butter, however, provides the ideal rescue: It moistens and flavors the fish to luxurious extremes, yielding forkfuls that literally melt in your mouth. A note of caution: This is rich, so if anyone at your table is sporting a pacemaker, you might want to sound a warning, or serve with a side of Lipitor.

Butter-Braised Fish

Time: 45 minutes Difficulty: Moderate Serves 4

1 cup heavy cream

1 pound (4 sticks, seriously) cold butter, cut into pieces, plus 2 tablespoons

4 skinless fish fillets, about 6 ounces each

4 large leeks, white and green parts, thoroughly washed and roughly chopped

Salt and freshly ground pepper, to taste

1. Preheat the oven to 300 degrees. Pour the cream into an ovenproof pot over high heat and add 1 cup of water. When it comes to a boil, turn down the heat to medium and whisk in the butter pieces. Keep the whisk going, and don’t let the liquid boil: You want the mixture to emulsify into a saucelike consistency. If it doesn’t, mix it in a blender.

2. Melt the 2 remaining tablespoons of butter in a saute pan over medium heat. Add the leeks and slowly saute until meltingly tender, about 12-15 minutes. Set aside.

3. Season the fillets with salt and pepper. Set the butter mixture over medium heat and bring it to a simmer. Gently add the fish. When it returns to a simmer, cover the pot and place it in the oven. Cook for 10-15 minutes.

4. When the fish is done cooking, return the pan with the leeks to the stove over medium-low heat, just to warm them through. Add ¼ cup of the fish cooking liquid and salt and pepper to taste.

5. To serve, divide the leeks into four bowls and top with a fillet.