Barbecue Mixed Salad

Name: Barbecue Mixed Salad
Ingredients: 1 piece (1/2 pound) butternut squash, seeded, peeled, and sliced lengthwise 1/2 inch thick; 1 red pepper, stemmed, seeded, halved crosswise, and cut lengthwise into 8 strips; 2 zucchini, halved crosswise and thinly sliced lengthwise; 5 cloves garlic, unpeeled; 1/2 large red onion, cut into 1 1/4-inch wedges; 1 tablespoon extra-virgin olive oil; 2 teaspoons verjus or freshly squeezed lemon juice; 2 sprigs fresh rosemary; Sea salt and freshly ground pepper