This is the BEST steak sandwich you can make! Tender slices of perfectly seared flank steak on a soft ciabatta bun, topped with sweet caramelized onions, zesty arugula, and your favorite condiments. This meaty sandwich is full of flavour and perfect for lunch or dinner.
Ingredients
2poundsflank steak
½teaspoonsalt, or to taste
½teaspoonblack pepper, or to taste
4ciabatta buns
2cupbaby arugula
4tablespoonspesto
4tablespoonsmayonnaise
4tablespoonsmustard
Caramelized Onion
3tablespoonsbutter
2large onions, sliced
1teaspoonsugar
½teaspoonsalt, or to taste
½teaspoonpepper
Instructions
Start with the caramelized onions. Heat a large skillet over medium-low heat and add the butter to melt. Place the sliced onion, salt, and pepper into the pan, stir to combine and cook, stirring occasionally for 20-25 minutes until the onions have softened.
Add the sugar to the onions, and cook for an additional 10 minutes until the onions have browned and caramelized. Set aside until needed.
To cook the steak, heat oil a pan or skillet over medium-high heat. Season the steak liberally with salt and pepper and press the steak into the hot oil. Sear for 2-3 minutes per side until the steak is cooked to your liking. Remove and rest for at least 5 minutes before slicing.
Assemble the sandwiches by slicing the rested steak into thin strips and slice the bun open.
Spread some pesto on the bottom half of each bun, top with baby arugula, sliced steak, and caramelized onion. Spread mayo and mustard over the top bun and place it on the sandwich.