Equipment
Ingredients
Produce
- 2 yellow onion, thinly sliced
- 30 g arugula, washed and dried
Meat
- 350 g sirloin steak, thinly sliced against the grain
Pantry & Dairy
- 2 ciabatta rolls, halved horizontally
- 30 g mayonnaise
- 15 g prepared horseradish
- 15 g unsalted butter
- 15 ml olive oil
- 3 g kosher salt
- 2 g black pepper, freshly cracked
Nutrition (per serving)
Method
Combine the mayonnaise and prepared horseradish in a small mixing bowl. Stir well and set aside to allow the flavors to meld.
Heat the unsalted butter and olive oil in a cast iron skillet over medium-low heat. Add the sliced onions and a pinch of salt. Cook slowly, stirring occasionally, until deeply golden and sweet.
Remove the caramelized onions from the skillet and set aside. Wipe the skillet clean if necessary, then increase the heat to high. Season the thinly sliced steak generously with the remaining salt and black pepper.
Place the seasoned steak slices into the hot skillet in a single layer. Sear quickly on both sides until browned but still tender, reaching an internal temperature of 54°C/130°F for medium-rare.
Lightly toast the halved ciabatta rolls until the cut sides are crisp and golden brown.
Spread a generous layer of the horseradish sauce onto the bottom halves of the toasted rolls. Layer evenly with fresh arugula, the warm seared steak slices, and a mound of caramelized onions. Top with the remaining roll halves and serve immediately.
Chef's Notes
- Partially freezing the sirloin for 20 to 30 minutes before cutting makes it significantly easier to achieve paper-thin, even slices.
- True caramelized onions cannot be rushed. Resist the urge to turn up the heat, which will fry and crisp the onions instead of slowly coaxing out their natural sugars.
- A teaspoon of balsamic vinegar stirred into the onions during their final minute of cooking provides a wonderful acidic contrast to the rich beef.
- If your pan is small, sear the steak in two batches. Overcrowding the pan will cause the meat to steam rather than sear, resulting in a grey, unappetizing color.
Storage
Refrigerator: 3 days — Store cooked steak, onions, and sauce in separate airtight containers.
Reheating: Gently warm the steak and onions in a skillet over low heat until just heated through. Assemble on freshly toasted bread.
