Gaucho Steak Sandwiches

I've been very hungry for steak lately, and thought these steak sandwiches would be a fun treat for the hubby and I to try. This is a slightly modified version of a Rachael Ray recipe; I decided not to involve the oven and not to drench the steak in the chimichurri sauce. I also used my own favorite cheese, and I halved the recipe -- although both the hubby and I agree that this would easily still feed four people.

If you've never tried chimichurri, it's an Argentinean condiment that's sort of like a dressing, but that is typically used as a sauce or marinade. The basic components are parsley, garlic, vinegar, oil, and chiles of some sort, although I've seen dozens of versions. Chimichurri is sometimes referred to as "gaucho," which is also the term for a South American cowboy.

Chimichurri is designed to complement beef because, well, Argentineans like their beef. They eat more of it than anyone else in the world. The Pampas, which are low-lying grasslands, are excellent grazing lands for beef cattle.

I included that last part just to prove that I was listening in my eleventh-grade history and geography class. Thank you.

Gaucho Steak Sandwiches
Serves 4

1/2 c. lightly packed flat-leaf parsley
3 garlic cloves
1/2 jalapeño pepper, seeded and roughly chopped
1/4 tsp. crushed red pepper flakes
Juice of 1 lime
2 1/2 Tbsp. red wine vinegar
1/2 c. plus 1/2 Tbsp. olive oil
1/2 tsp. kosher salt
1/4 tsp. freshly ground pepper
1/2 small red onion, thinly sliced and chopped
2 plum tomatoes, chopped
1 1/4 lb. sirloin or other steak
Steak seasoning
4 sub-style sandwich rolls, split
4 oz. whole-milk mozzarella, shredded

1. In a food processor, pulse the parsley, garlic, and jalapeño a few times, until the mixture is finely chopped. Add the red pepper flakes, lime juice, vinegar, 1/2 cup olive oil, salt, and pepper. Process until combined.

2. Pour half the sauce in a bowl and add the sliced red onion and tomato wedges. (Save the remaining sauce for passing at the table.)

3. Heat a large, preferably cast-iron skillet over medium-high heat. Season steak with steak seasoning. Add the remaining ½ Tbsp. olive oil to the pan. Cook the steak 5-10 minutes per side, and then let rest for at least 5 minutes. Thinly slice steak across the grain.

4. Heat a nonstick skillet to medium heat. For each sandwich, add one-fourth the steak, and pour some of the tomato and onion mixture over the top. Cook until steak is heated through.

5. Put steak mixture on a split roll, and top with one-fourth of the cheese.