Directions

1. Marinate the steak in 25 ml of olive oil for an hour to tenderize.
2. Season steak liberally with salt and pepper. Heat a cast-iron pan and hard sear the steak for roughly 4 minutes per side. Remove from pan cover with Swiss cheese slices and rest at room temperature, tented, for 5 minutes.
3. Meanwhile, grill bread, and reheat caramelized onions.
4. Toss arugula with olive oil, lemon juice, salt and pepper.
5. Place mayonnaise on the bottom slice of bread then cover with caramelized onions.
6. Slice steak thinly against the grain and shingle on top of onions, being sure to capture all the cheese.
7. Top with arugula salad, then top piece of bread covered with Dijon mustard.