Take the steak out of the refrigerator an hour before cooking to bring it to room temperature. Generously season all sides with salt and pepper while it rests.

Heat a large, non-stick skillet over medium-high heat with a drizzle of oil or pork lard. Sear the steak on the fat cap for about 1 minute to render some fat. Then, cook the steak for 2–3 minutes on each side until it reaches your desired doneness. For extra richness, add 2 tablespoon of butter during the last flip and baste the steak with the melted butter.

Remove from the skillet, set aside, and let the steak rest for 5 minutes before slicing thinly.

In the same skillet, add the sliced onions and season with 1 teaspoon salt. Cook over medium heat, stirring occasionally, for 10–15 minutes until the onions are caramelized. For a touch of sweetness, drizzle 1 teaspoon of balsamic glaze over the onions and cook until they’re deep golden brown. Set aside.

Slice the ciabatta loaf and toast each half until golden and crispy, either in a toaster or in a pan over medium heat.

Spread lemon herb aioli on the toasted ciabatta halves. Layer with arugula, sliced steak (add a pinch of salt if desired), caramelized onions, and an extra drizzle of balsamic glaze.

Slice the sandwich in half, serve warm, and enjoy! Warning: Be careful who you make this for—you might get a proposal!