| Herb Paste | |
| ½ | cup packed fresh cilantro leaves |
| 3 | medium garlic cloves, roughly chopped |
| 3 | medium scallions, roughly chopped (about ⅓ cup) |
| 1 | medium jalapeño chile, stemmed and roughly chopped (see note) |
| ½ | teaspoon ground cumin |
| ¼ | cup vegetable oil |
| 1 | tablespoon fresh lime juice |
| Steak | |
| 1 | flank steak (1½ to 1¾ pounds), trimmed of excess fat and cut lengthwise (with grain) into 4 equal pieces (see below) |
| 1 | tablespoon kosher salt or 1½ teaspoons table salt |
| ½ | teaspoon sugar |
| ½ | teaspoon ground black pepper |
| 2 | tablespoons vegetable oil |
| Tacos | |
| 12 | (6-inch) corn tortillas, warmed (see note) |
| Fresh cilantro leaves | |
| Minced white or red onion | |
| Lime wedges |
1. FOR THE HERB PASTE: Pulse cilantro, garlic, scallions, jalapeño, and cumin in food processor until finely chopped, ten to twelve 1-second pulses, scraping down sides as necessary. Add oil and process until mixture is smooth and resembles pesto, about 15 seconds, scraping down sides of workbowl as necessary. Transfer 2 tablespoons herb paste to medium bowl; whisk in lime juice and set aside.
2. FOR THE STEAK: Using dinner fork, poke each piece of steak 10 to 12 times on each side. Place in large baking dish; rub all sides of steak pieces
evenly with salt and then coat with remaining herb paste. Cover with plastic wrap and refrigerate at least 30 minutes or up to 1 hour.
3. Scrape herb paste off steak and sprinkle all sides of pieces evenly with sugar and pepper. Heat oil in 12-inch heavy-bottomed nonstick skillet over medium-high heat until smoking. Place steak in skillet and cook until well browned, about 3 minutes. Flip steak and sear until second side is well browned, 2 to 3 minutes. Using tongs, stand each piece on a cut side and cook, turning as necessary, until all cut sides are well browned and internal temperature registers 125 to 130 degrees on an instant-read thermometer, 2 to 7 minutes. Transfer steak to cutting board and let rest 5 minutes.
4. FOR THE TACOS: Using sharp chef’s knife or carving knife, slice steak pieces across grain into ⅛-inch-thick pieces. Transfer sliced steak to bowl with herb paste-lime juice mixture and toss to coat. Season with salt. Spoon small amount of sliced steak into center of each warm tortilla and serve immediately, passing toppings separately.