Ah, the kick-ass sauce! A grilled steak needs some kick and I love chilies. I like using Hatch chiles from New Mexico; their season is rather short but worth it. Fresno chiles also work well. I find they have a nice round flavor, medium heat and marry well with the sweet onions, balsamico, and garlic. Hanger steak is sometimes called the “butcher’s cut.” It is an earthy, meaty steak that appeals to everyone who likes meat with texture. Skirt steak is a viable substitute, but rib-eye is not (though I love rib-eyes, they can be a bit fatty). The steaks are simply rubbed with sea salt and a generous amount of freshly ground black pepper. The trick is to sear the hell out them. No timidity here; let the cast-iron skillet do its duty. If it’s summer, by all means use a charcoal grill. For a wine that sucks up the heat, choose a Barbera from Piedmont.
Preheat the oven to 375 degrees.
Trim the steak and season with sea salt and black pepper. Bring it to room temperature.
To make the salsa, put the garlic, onion, chiles, and olive oil into a cast-iron skillet. Roast in the oven for about 10 minutes. Remove from the oven, deglaze with the balsamico and then purée everything in a food processor fitted with a metal blade until chunky.
Prepare a medium-hot grill. Sear the hanger until dark mahogany in color and crispy on all sides — this takes vigilance, but only about 8 minutes total. Hanger should be rare to medium-rare. Let the steak rest for 5 minutes, then slice.
Serve with the salsa.