Step 1

For the lemon butter: Whisk together the lemon juice, salt, pepper, lemon zest and butter in a deep medium bowl until well blended (mixture will be like a thick sauce). Set aside until ready to use.

Step 2

For the halibut and crispy shallots: Combine the olive oil, lemon juice, garlic, salt, pepper and garlic in an 8-by-8-by-2-inch glass dish. Whisk the marinade to blend. Add the halibut and turn several times to coat evenly. Let stand 15 to 20 minutes.

Step 3

Combine the grapeseed oil and shallots in a medium heavy saucepan over medium-high heat. Cook, stirring often, until the oil heats up and the shallots turn golden brown, 5 to 7 minutes. Transfer the shallots with a slotted spoon to several layers of paper towels to drain and crisp. Sprinkle with salt and pepper just before using.

Step 4

Heat a large dry nonstick skillet over medium-high heat. Lift the halibut from the marinade, letting the excess drain off. Add the halibut to the hot skillet and sear 3 minutes. Turn the fish over using a flexible metal spatula. Sear until still slightly pink in the center, about 3 minutes longer, depending on thickness. Transfer the halibut to plates. Top with a generous dollop of lemon-butter and pile the shallots alongside or scatter around the fish. Garnish with the lemon wedges and serve.