Pre-heat the grill to medium, or set a grill pan over medium heat. Once hot, brush with oil.
Cook the corn for about 20 minutes, flipping with tongs every once in a while. Also, cook the scallions for about 10 minutes, flipping occasionally as well. Remove both from the heat when charred, cooked and softened. Set aside.
Heat 5 tablespoons of olive oil in a skillet over high heat. Once the oil is hot, add the tomatoes, salt and pepper, and cook for 6 to 7 minutes until charred and softened. Remove from the heat, making sure to reserve the oil and tomato juices as well.
Shave the corn kernels off the cobs and place in salad bowl. Cut white and light green parts of the scallions into 1-inch pieces and add to the bowl. Add the mint, chives, vinegar, and the reserved oil and juices from the tomatoes. Mix well. Incorporate the tomatoes. Gently toss and serve.