How to Make It
In a bowl, whisk all of the ingredients.
Light a grill. Remove all but the last layer of green husk from the corn. In a bowl, soak the corn in water for 10 minutes, then drain.
In a bowl, toss the scallions with 2 tablespoons of the oil; season with salt and pepper. In another bowl, coat the chicken with the remaining 2 tablespoons of oil and the rosemary; season with salt and pepper.
Grill the corn, scallions and chicken over moderate heat, turning occasionally, until the corn and scallions are lightly charred and the chicken is cooked through, 5 minutes for the scallions and 15 minutes for the corn and chicken. Let the chicken rest for 5 minutes, then thinly slice across the grain.
Chop the scallions into 1-inch pieces. Remove the husks and cut the corn kernels off of the cobs. Transfer the scallions and corn to a large bowl; add the tomatoes, basil and half of the dressing and toss. Transfer the salad to a platter. Top with the chicken and garnish with chives and lime zest. Serve the remaining dressing at the table.