Cobia (Lemonfish) With Walnut Purée And Asparagus
Barton Seaver / For Cod And Country
Cobia is a very meaty fish that can stand up to grilling. It must be cooked slowly, though; it is so dense that the outside will dry out long before the inside cooks if it is subjected to high heat for too long. This recipe also works with the oven and broiler: cook the fish at 250°F for 20 minutes, then transfer the fish to the bottom rack while you broil the asparagus until crispy. The asparagus should be browned and the fish will be done by that point.
2 bunches asparagus (about 2 pounds), heavy bottoms trimmed
1 small onion, peeled
3 cloves garlic, peeled
½ cup extra-virgin olive oil
½ cup walnuts
Juice of 1 lemon
¾ cup cold water
Four 5-ounce portions cobia fillet
Blanch the asparagus in boiling water for 2 minutes (if the spears are particularly thin, shock in ice water and drain). Set aside.
For the walnut purée, place the onion and garlic with the olive oil in a small pot. Simmer over medium heat until the onion begins to soften, about 5 minutes. Add the walnuts and continue to cook for 4 minutes. Remove the pan from the heat and stir in the lemon juice. Carefully transfer the contents of the pot to a blender. Starting on very low speed, pulse the mixture a few times to get the puree going and begin to gradually increase the speed. Add the water and continue to blend until it is a smooth purée. Season to taste with salt. The sauce will keep refrigerated for up to 5 days.
For the cobia, prepare grill. Place the cobia on the hottest part of the grill and cook for 4 minutes. Rotate the grate so the fish is over the coolest part of the grill and cover the grill. Cook for 12 minutes. When the fish is almost cooked through, place the asparagus over the hottest part of the grill and cook until charred.
To serve, brush the plates with a generous spoonful of the walnut purée and place the asparagus on it. Place the fish on top of the asparagus and serve.