Step 1

1 Line a small rimmed baking sheet with aluminum foil or parchment paper; place the steaks on it and freeze (uncovered) for 30 minutes

Step 2

2 Preheat the oven to 160 degrees, or its lowest temperature (see headnote)

Step 3

3 Brush both sides of the chilled steaks with the vegetable oil, then generously season with the kosher salt and black pepper

Step 4

4 Heat a heavy skillet, preferably cast-iron, over high heat

Step 5

5 Add the steaks and sear for 60 seconds on each side, or until they reach your desired level of char

Step 6

6 Briefly sear the fat on the side of each steak until it is lightly browned (use tongs to hold the meat upright)

Step 7

7 Discard the foil or parchment from the baking sheet, then place the steaks directly on the baking sheet

Step 8

8 Insert the probe of an oven-safe digital thermometer into the thickest part of one steak

Step 9

9 Transfer to the oven; slow-roast until the meat registers an internal temperature of 133 degrees

Step 10

10 The time may vary depending on the thickness of the steak and your oven temperature, but figure on at least 50 minutes to 1 hour

Step 11

11 The meat will be an even medium-rare, rosy pink throughout

Step 12

12 Meanwhile, combine the olive oil and rosemary in a small skillet over medium-low heat; cook for 5 to 10 minutes, stirring occasionally, until fragrant

Step 13

13 Remove from the heat; scrape the rosemary and all but about a teaspoon of the oil into a small bowl

Step 14

14 Return the skillet to the stove top, over medium-high heat; add the lemon halves, cut sides down

Step 15

15 Cook until the cut sides are well browned and charred in spots

Step 16

16 Use tongs to transfer them to a plate, cut sides up

Step 17

17 Brush the finished steaks lightly with the rosemary-infused oil, and season lightly with the flaky salt

Step 18

18 Let the meat rest for a few minutes, then slice and serve, with the remaining infused oil and the charred lemon halves, for squeezing