Flat Iron with Chimichurri and Smashed Potatoes

For potatoes: Place potatoes in a medium saucepan. Add water to completely cover. Bring to a boil over medium-high; add 1 tablespoon salt and reduce heat to a simmer. Simmer until potatoes can be easily pierced with a paring knife, about 20 minutes. Drain and let stand until cool enough to handle.

Arrange potatoes on a baking sheet. Gently smash each potato with the bottom of a glass or measuring cup just until split open but not breaking apart. Brush potatoes with olive oil and season with thyme, salt and pepper.

Meanwhile, make chimichurri: Grill jalapeño and shallot, covered, over medium heat until blackened on all sides and quite soft, about 5 minutes. (Do not turn off grill.) Place jalapeño in a small bowl and cover with plastic wrap; let stand about 10 minutes. Peel, stem and seed jalapeño.

In a food processor, combine jalapeño, shallot, cilantro, mint, basil, vinegar and garlic. Process until finely chopped. Drizzle in oil while processor is running. Stir in kosher salt.

For steak: Rub steak with olive oil and season very generously with salt and pepper. Place steak and smashed potatoes on grill rack; cover. Grill steak 10 to 12 minutes for medium-rare (145°) or 12 to 15 minutes for medium (160°), turning once halfway through grilling. Grill potatoes 10 minutes or until golden brown and crisp, turning once halfway through grilling. Transfer steak to a plate, tent with foil and let rest 5 minutes.

To serve, slice steak thinly across the grain with a knife at a 45-degree angle. Serve with potatoes and chimichurri.