Step 1

Pat steak dry with paper towels and place on a clean plate. Season very generously all over with salt and pepper. (Think four-fingered pinches of salt—rich proteins like steak need a lot more salt than you might think.) Let it sit at room temperature while you prep your other salad components, at least an hour if possible. (Don't worry: It's safe, and a room-temperature steak will cook more evenly than it will straight out of the fridge.)

Step 2

Salad dressing time! Peel and finely chop 1 shallot and transfer to a medium bowl. Add 1 Tbsp. mustard and 1 Tbsp. vinegar and whisk to combine. Here comes the fun part: Whisking constantly, slowly stream in 5 Tbsp. olive oil until dressing is thick and emulsified. The word "slowly" is key here—if you add the oil all at once, you won't get the creamy, nicely-incorporated vinaigrette you're after. Whisk in 1 Tbsp. water to thin the dressing out a bit. Season with salt to taste, and add another splash of vinegar if you like—it should taste good and punchy.

Step 3

Prep your other salad ingredients. Slice 1 pint cherry tomatoes in half and transfer to a medium bowl. Slice 2 cucumbers into thin coins and transfer to bowl with tomatoes. Separate lettuce leaves and arrange on a large platter. Cover the lettuce with damp paper towels and chill in the fridge until you’re ready to assemble.

Step 4

Heat a dry cast-iron skillet over medium-high. Pat steak dry again (the salt will have drawn out some moisture). Seriously: You want the meat to be as dry as possible, which is key to getting the handsome, crusty sear you're after. Rub steak with remaining 1 Tbsp. oil. When we're searing things like steak or chops, we like to oil the surface of the meat rather than the surface of the pan—this allows us to use less oil, and also cuts down on (the inevitable) smoke that comes with this kind of cooking. Speaking of which, this is a good time to turn on the vent above your stove, open a window, and/or get ready to (temporarily!!) deactivate your smoke detector .

Step 5

Using tongs, gently lay steak in preheated pan. Cook undisturbed—as in, resist the urge to futz with it!—until a golden brown crust forms, about 3 minutes. Turn steak and cook on second side for another 3 minutes.

Step 6

Turn steak to sear around thinner sides and fat cap until browned, then continue to cook 1 minute per side until steak is medium-rare in the center, 3–5 minutes longer. If you have an instant-read thermometer and you’re uncertain about doneness, insert it into the center of the steak and look for a reading of 120–125°. Continue to cook until you get there.

Step 7

Remove skillet from heat. Transfer steak to cutting board briefly to rest. Wipe out skillet with a paper towel to remove any blackened oil. Let skillet cool 1–2 minutes, then heat over medium-low. Have a spoon close at hand. Return steak to skillet. Add 2 Tbsp. butter and 2 sprigs thyme and tilt skillet toward you so butter foams and pools along one side. Make sure thyme is swimming in the butter so it can really infuse. Use spoon to scoop up foamy butter and baste over top of steak constantly until butter is fragrant and browned, about 1 minute. Transfer steak to cutting board. It should rest at least 10 minutes—you never want to cut into a steak without resting first, otherwise it will lose a lot of juiciness.

Step 8

Build your salad: Remove platter of lettuce from refrigerator; season with salt and pepper. (We always like to season our greens before we dress them.) Whisk dressing to combine and drizzle about half over lettuce.

Step 9

Season tomatoes and cucumbers with salt and pepper. (In case you haven't noticed by now, making sure to season all of your components is key.) Toss with a couple of tablespoons of dressing and arrange in a row along one side of lettuce.

Step 10

Halve 1 avocado, remove pit, and thinly slice. Fan out slices and arrange over top of lettuce in another row opposite tomatoes and cukes.

Step 11

Once steak has rested, thinly slice crosswise and shingle slices down across middle of platter. Season steak and avocado with more salt and pepper, then drizzle remaining dressing over avocado and steak. So fancy!