Grilled Jalapeño-Marinated Steak Sandwiches With Charred Onions and Cotija Mayo Recipe

I'm all about grilling sandwiches. Over the past few years, I've come to see my grill as the ultimate sandwich-making machine—I can cook just about all my sandwich ingredients on it, pile them on bread, and then use the remaining heat from the coals to either press or heat the sandwich. Plus it can all be done en masse for a crowd.

So far, this approach has churned out some great results, like giant Italian heroes, Cubanos, sweet and spicy chicken sandwiches, and these merguez sandwiches with caramelized onions, Manchego cheese, cilantro, and harissa mayo—my most successful to date.

Those merguez sandwiches stand out because the ingredients add up to something that's greater than the sum of their parts, with a singular cohesion that just plain works. My goal was to replicate that success, and I found it in the form of these jalapeño-marinated steak sandwiches.

A Beef for Bread

Starting out with steak for my sandwich was a risky move; I've been the victim of overly chewy or tough-to-bite-through steak sandwiches more times than I care to count. Still, I know my beef, and figured I could side-step those pitfalls with a little know-how.

First I had to find the right cut, something that would balance tenderness, beefiness, and price. With those considerations in mind, I was left with my three favorite steaks to choose from: skirt, flank, and hanger.

I went with hanger, though if you can't find it, flank or skirt will do just as well. The steak I had picked up was on the thick side, though, so I butterflied it open to give it more surface area for searing and picking up flavor.

Hanger steak has a loose, open structure that makes it ideal for sopping up marinades. I made a potent mixture of lime juice, jalapeños, olive oil, garlic, brown sugar, soy sauce, vinegar, salt, and pepper. This highly acidic and super spicy marinade didn't need much time to impart its flavor, so I only let the meat soak for as long as it took to prep the rest of the ingredients and get the fire going.

Complements and Contrasts

As I considered what the other players would be, the jalapeño marinade had me thinking of taking the sandwich in a Mexican or Tex-Mex direction. Being a bit of a sauce fiend as well, I ended up packing most of the complements and contrasts into a mayonnaise, laden with cotija cheese, chili powder, cayenne pepper, sour cream, and lime juice—a combo influenced by elotes (Mexican street corn). It's nice and easy, too, delivering salty, tangy, creamy, and earthy notes in just one quick slather.

Thanks to the powerful sauce, I didn't need too much else to round out the sandwich. I decided to add in some cilantro for freshness and onions, grilled until charred and semi-soft, for a little crispy sweetness.

The Build

With the flames now going strong, it was time to get this sandwich grilled. I built a two-zone fire and grilled the hanger steak over direct heat while the fire was at its hottest. The steak seared in almost no time, and the meat hit a perfect medium-rare at the same time the outside was deeply browned—any more than medium-rare with hanger steak and it'll start getting too chewy. I rested the steak as the onions grilled, and then cut it against the grain into short one-inch strips to make sure each piece was tender and easy to eat in sandwich form.

For the bread, I split a good-quality baguette into four pieces, halved them, and then brushed them extra-virgin olive oil, toasting them on the grill. Once they were a little brown and crisp, I slathered on my mayonnaise, followed by slices of steak, a handful of cilantro, and some charred onions, before closing them and throwing them back on the cooler side of the grill.

At this point I'd been cooking for about 20 minutes and the fire had reached a medium-heat range, meaning that the I could stick the sandwiches into the covered grill and let them slowly warm through without worrying about drying out the steak or burning the bread.

Now came the moment truth. Would this latest sandwich creation hold up to what inspired me to make them in the first place?

Luckily, I was not left disappointed. The steak itself was pretty incredible, with the marinade embedding a fruity, tangy flavor and a slight touch of heat. The mayo came through with a bold but complementary touch, with brightness from the cilantro and a sweet, subtly earthy note from the grilled onions. In the crusty toasted baguette, I'll be damned if these steak sandwiches aren't pretty killer.