This is a flavorful steak sandwich with juicy slices of meat and that wonderful punchy parsley sauce from Argentina known as chimichurri. It works with different cuts that can be grilled or cooked on a skillet.
Cut the 12 ounces sirloin steak at room temperature into two equal pieces.
Season the meat with kosher or coarse salt and freshly ground black pepper. Let stand for 10 minutes before cooking.
Heat 2 tablespoons olive oil or butter (or 1 tablespoon each) in a large skillet. Add meat and cook over medium heat for 4-5 minutes on each side, depending on the thickness of the meat and how juicy you like it. It can vary a lot.
Transfer to a plate and let it rest for 5 minutes to allow the juices to re-distribute.
To assemble the sandwiches:
Cut 2 long, hard rolls like French bread, ciabatta or similar in half. Lightly toast them if you want to. I don't if using fresh bread.
Cut the steak across the grain and, dividing evenly, place the slices over the bottom half of the bread, making sure no juices are left behind. The bread must be embedded in meat juice to get a tastier sandwich.
Top the meat with a few tablespoons of the 4 tablespoons chimichurri sauce. If using, place tomato slices, thinly sliced red onions or roasted red pepper strips.
Close the sandwiches with the remaining bread. Eat immediately.
Notes
Chimichurri: though you technically can make it at the last moment, it's best to make it in advance. Leave it marinating for a few days to allow the flavors to meld and become one amazingly flavorful powerhouse.Bread: Use simple crusty bread like ciabatta and warm it before putting the sandwiches together. Soft rolls don't have the same effect and can become soggy quickly. We don't want that.Meat: I use sirloin steak, but any flavorful meat works, like hanger steak, skirt steak, NY ribeye steaks. As do barbecued meat leftovers. Leaner cuts like beef tenderloin can also be used, but it's not my favorite; not enough fat to give it flavor!