Prep the steak: Pat the steak dry with paper towels. Season generously on both sides with salt and pepper. Let it sit at room temperature for 15 to 20 minutes while you prep the beans and garlic.

Trim and rinse the beans: Snap off the stem ends. Rinse and dry well so they sauté instead of steam.

Heat the pan: Set a large skillet (cast iron is best) over medium-high heat. Add 1 tablespoon olive oil and let it shimmer.

Sear the steak: Lay the steak in the hot pan. Don’t move it for 2 to 3 minutes to build a crust. Flip and sear the second side for another 2 to 3 minutes. Adjust for thickness and desired doneness.

Add butter and baste: Reduce heat to medium. Add 1 tablespoon butter and half the minced garlic. Tilt the pan and spoon the garlicky butter over the steak for 30 to 60 seconds.

Rest the steak: Transfer the steak to a plate and tent loosely with foil. Rest 5 to 10 minutes so the juices redistribute.

Cook the green beans: In the same pan, add another teaspoon of olive oil if needed. Toss in the green beans, a pinch of salt, and black pepper. Sauté 4 to 6 minutes, stirring occasionally, until bright green and crisp-tender.

Garlic butter finish: Push the beans to the side. Add the remaining 2 tablespoons butter to the empty space, then the remaining garlic. Cook 15 to 30 seconds, just until fragrant, then toss the beans in the garlic butter. Add a squeeze of lemon and a pinch of red pepper flakes if using.

Slice the steak: Slice against the grain into strips. If you collected any resting juices, pour them back into the pan to mix with the beans and sauce.

Serve: Return the steak to the pan or plate it over the beans. Finish with lemon zest and chopped parsley or thyme. Taste and adjust salt and pepper.