1 large red onion , peeled and cut crosswise into four 1/2-inch-thick rounds
3 medium zucchini (about 1 pound), ends trimmed, sliced lengthwise into 3/4-inch-thick planks
1/4 cup plus 2 tablespoons extra virgin olive oil
Kosher salt and ground black pepper
1 small garlic clove , minced or pressed through garlic press (about 1/2 teaspoon)
1 teaspoon finely grated zest from 1 lemon plus 1 tablespoon juice
1/4 teaspoon Dijon mustard
1 tablespoon chopped fresh basil leaves
PROCESS:
1. Thread onion rounds, from side to side, onto 2 metal skewers. Brush onion and zucchini evenly with ¼ cup olive oil and season with 2 teaspoons kosher salt (or 1 teaspoon table salt) and pepper to taste.
2. Whisk remaining 2 tablespoons olive oil, garlic, lemon zest and juice, mustard, and ½ teaspoon kosher salt (or ¼ teaspoon table salt) together in small bowl; set aside.
3. Grill vegetables over medium heat, turning once, until tender and caramelized, 10 to 12 minutes (move vegetables as needed to ensure even cooking). Transfer vegetables to platter; remove skewers from onion and discard any charred outer rings. Rewhisk vinaigrette and pour over vegetables. Sprinkle with basil and serve.
