This is a fresh, feel-good salad that goes well with all grilled meats, especially during the hot summer months.
Technique tip: Salting and resting the watermelon will help to draw out excess water. This will accentuate grill marks and allow better absorption of the dressing.
Preheat the grill to high heat or 450°F.2.
Cut the watermelon into 1¼-inch thick rounds. Generously salt both sides of each slice and put them on a wire rack set over a rimmed baking pan for 15 minutes.3.
Rinse the salt from the watermelon rounds and pat them dry with paper towels. Brush the watermelon pieces with 1/4 cup of the oil. Put the watermelon on the grill over direct heat and cook until grill marks appear, about 3 minutes on each side. Remove the watermelon from the grill, trim and discard the rind, and cut it into 1-inch cubes, picking out as many seeds as you can.4.
In a medium bowl, combine the watermelon, tomatoes, onion, the remaining 1/4 cup olive oil, vinegar, sugar and basil. Season with salt and pepper to taste, cover the bowl, and refrigerate for 1 hour.5.
Sprinkle the feta cheese over the top before serving.