Prep the steak: Pat the steak dry on all sides. Season generously with salt and pepper.
Let it sit at room temperature for 20–30 minutes while you prep the salad. This helps it cook evenly.
Make the dressing base: In a medium bowl, whisk together egg yolk (or mayo), anchovy, garlic, Dijon, and lemon juice until smooth. The mixture should look creamy and unified.
Emulsify: While whisking constantly, slowly stream in the oil until the dressing thickens and looks glossy.
If it gets too thick, whisk in 1–2 tablespoons water to loosen. Stir in the Parmesan. Taste and season with salt and pepper.
You want bright, savory, and lightly garlicky.
Prep the salad: Wash and dry the romaine thoroughly. Toss the lettuce with a few spoonfuls of dressing to lightly coat. Add croutons and half the Parmesan.
Toss again. Hold off on the rest of the dressing until serving.
Heat the pan: Set a heavy skillet (cast iron is best) over medium-high heat. Add the oil and heat until it shimmers and just begins to smoke.
Sear the steak: Lay the steak in the hot pan.
Don’t move it for 2–3 minutes to build a crust. Flip and cook another 2–4 minutes, depending on thickness and desired doneness. For medium-rare, aim for an internal temp of 130–135°F (54–57°C).
Optional butter baste: Add butter, smashed garlic, and herbs to the pan.
Tilt the pan and spoon the foaming butter over the steak for 30–45 seconds. This adds richness and aroma.
Rest the steak: Transfer to a cutting board and rest for 5–10 minutes. This keeps the juices inside.
Slice against the grain into thick strips.
Finish the salad: Add more dressing as needed to coat lightly—avoid overdressing. Scatter the remaining Parmesan on top.
Plate and serve: Divide the salad onto plates. Top with sliced steak or serve the steak on the side.
Add a squeeze of lemon over everything for a bright finish.