Ingredients
Fish
4 (6-ounce) skinless white fish fillets, 1 inch thick
Kosher salt
4 ounces frozen artichoke hearts, thawed, patted dry, and sliced in half lengthwise
1 tablespoon cornstarch
¾ cup olive oil
3 garlic cloves, minced
½ onion, peeled
Vinaigrette
4 ounces cherry tomatoes
½ small shallot, peeled
4 teaspoons sherry vinegar
Kosher salt
½ teaspoon pepper
1 tablespoon chopped fresh parsley
2 ounces cherry tomatoes, cut into 1/8-inch-thick rounds
Directions
1
FOR THE FISH: Adjust oven racks to middle and lower-middle positions and heat oven to 250 degrees. Pat fish dry with paper towels and season each fillet with 1/4 teaspoon salt. Let sit at room temperature for 20 minutes.
2
Meanwhile, toss artichokes and cornstarch in bowl to coat. Heat 1/2 cup oil in 10-inch nonstick skillet over medium heat until shimmering. Shake excess cornstarch from artichokes and add to skillet; cook, stirring occasionally, until crisp and golden, 2 to 4 minutes. Add garlic and continue to cook until garlic is golden, 30 to 60 seconds. Strain oil through fine-mesh strainer into bowl. Transfer artichokes and garlic to ovenproof paper towel–lined plate and season with salt. Do not wash strainer.
3
Return strained oil to skillet and add remaining ¼ cup oil. Place onion half in center of pan. Let oil cool until it registers about 180 degrees, 5 to 8 minutes. Arrange fish fillets, skinned side up, around onion (oil should come roughly halfway up fillets). Spoon a little oil over each fillet, cover skillet, transfer to middle rack, and cook for 15 minutes.
4
Remove skillet from oven. Using 2 spatulas, carefully flip fillets. Cover skillet, return to middle rack, and place plate with artichokes and garlic on lower-middle rack. Continue to cook fish until it registers 130 to 135 degrees, 9 to 14 minutes longer. Gently transfer fish to serving platter, reserving 1/2 cup oil, and tent fish loosely with aluminum foil. Turn off oven, leaving plate of artichokes in oven.
5
FOR THE VINAIGRETTE: Process whole cherry tomatoes, shallot, vinegar, 3/4 teaspoon salt, and pepper with reserved 1/2 cup fish cooking oil in blender until smooth, 1 to 2 minutes. Add any accumulated fish juice from platter, season with salt to taste, and blend for 10 seconds. Strain sauce through fine-mesh strainer, pressing on solids to extract as much liquid as possible (discard solids).
6
To serve, pour vinaigrette around fish. Garnish each fillet with warmed crisped artichokes and garlic, parsley, and tomato rounds. Serve immediately.