Begin by positioning your oven rack to the center and preheating your oven to 400 degrees Fahrenheit. While the oven heats, mince your garlic cloves very finely—I use a microplane or the smallest setting on my box grater for consistency. Chop your fresh parsley and set it aside in a small bowl. Having everything prepared before you touch the steak means you won't be scrambling once things get hot and fast.

Remove your flank steak from the refrigerator and pat it completely dry using paper towels. Moisture is the enemy of browning—wet meat steams instead of sears. Divide the steak into four equal portions by cutting perpendicular to the grain (this matters for tenderness later). Season each portion generously on both sides with kosher salt and freshly ground black pepper. I use about ¼ teaspoon salt per side per portion. Don't be shy—proper seasoning penetrates the meat and enhances its natural flavors.

Place a large cast iron skillet over medium-high heat and let it sit undisturbed for about 2 minutes until it's properly heated. You'll know it's ready when a drop of water immediately sizzles and evaporates. Add the vegetable oil to the hot pan and let it shimmer for about 30 seconds. Add 1 tablespoon of butter and watch it foam slightly—this is exactly what you want. Carefully place your seasoned steak portions into the pan. You should hear an immediate, confident sizzle. Do not move them. Let them sit undisturbed for exactly 3 minutes while they develop a golden-brown crust. This Maillard reaction creates the flavor foundation of your dish.

Using tongs, flip each steak portion carefully and sear the other side for another 3 minutes until both sides are evenly golden-brown. Your pan should still sound sizzly and confident. If the heat has dropped, you'll know the steaks have released enough moisture that browning has resumed. This is perfect.

Once both sides are seared beautifully, transfer the entire cast iron skillet directly into your preheated 400-degree oven. Bake for exactly 3 to 4 minutes. Your goal is to reach an internal temperature of 125 degrees Fahrenheit (medium-rare) when measured with an instant-read thermometer inserted into the thickest portion of a steak. The oven's gentle, surrounding heat ensures even cooking without overdrying this lean meat.

Carefully remove the cast iron skillet from the oven—the handle will be extremely hot, so use a kitchen towel or thick oven mitt. Transfer the steaks to a clean plate and let them rest for 5 minutes. This resting period is non-negotiable; it allows the juices to redistribute throughout the meat, keeping it tender and moist when you slice it. While the steaks rest, place your skillet back on the stovetop over medium-low heat. Add another tablespoon of butter and your minced garlic. Sauté for 1 to 2 minutes until the garlic becomes fragrant and just barely golden—don't let it brown or it will taste bitter.

Pour your dry white wine into the skillet with the garlicky butter. You'll immediately hear a sizzle as the wine hits the hot pan. Add any juices that have accumulated on the plate from your resting steaks—this is liquid gold for flavor. Increase the heat to medium-high and bring the mixture to a gentle boil. Let the wine reduce for about 5 minutes, using a wooden spoon to scrape up all the browned, caramelized bits stuck to the bottom of the pan. These fond particles contain concentrated beef and butter flavors. Watch the liquid decrease in volume and become slightly thickened and glossy. You'll know it's ready when you can run a spoon through the sauce and it leaves a brief trail before flowing back together.

Remove the skillet from heat and stir in your final tablespoon of butter and the fresh parsley. The butter creates a silky, emulsified finish. Taste the sauce and season with additional salt and pepper as needed. The wine should be the dominant flavor, with garlic as a supporting player and butter adding richness. Slice each steak portion against the grain into ¼-inch strips. This matters tremendously for tenderness. Arrange the slices on a plate, spoon the wine pan sauce generously over the top, and serve immediately while everything is hot. Good food is a good mood!