Charring tomatoes in a hot, dry skillet makes them smoky and flavorful; in combination with fresh herbs and spices, they elevate this dish from "everyday" to "ta-da!" Serve the tacos with reduced-fat sour cream.
- Heat a medium skillet over high heat until very hot. Add tomatoes and cook, turning occasionally with tongs, until charred on all sides, 8 to 10 minutes. Transfer to a plate to cool slightly. Cut the tomatoes in half crosswise; squeeze to discard seeds. Remove cores and chop the remaining pulp and skin.
- Cut chicken into 1-inch chunks; sprinkle with salt and pepper. Add 1 teaspoon oil to the pan and heat over high heat until very hot. Add the chicken and cook, stirring occasionally, until it is browned and no longer pink in the middle, 3 to 5 minutes. Transfer to a plate.
- Reduce the heat to medium and add the remaining 1 teaspoon oil. Add onion and cook, stirring, until softened, about 2 minutes. Add garlic and jalapeño and cook, stirring, until fragrant, about 30 seconds. Add lime juice, the chicken and tomatoes. Cook, stirring, until heated through, 1 to 2 minutes. Stir in cilantro and scallions. Divide the chicken mixture among tortillas. Serve with lime wedges.