How to Make It
In a medium bowl, toss the tomatoes with the jalapeño, shallot, cilantro and lime juice; season with salt. Let stand for 10 minutes, stirring occasionally.
Light a grill or preheat a grill pan and brush the grates with oil. Season the chicken with salt and grill over moderately high heat, turning once, until lightly charred on the outside and cooked through, about 12 minutes. Transfer the chicken to a cutting board and let rest for 5 minutes, then thinly slice.
Grill the tortillas in a single layer, turning once, until soft and pliable, about 30 seconds. Transfer the chicken to the tortillas and serve with the pico de gallo.