Zucchini is, at best, a bland foil for all kinds of fuller-flavored ingredients. Here baby zucchini has a tender crispness that is offset by a sprightly tomato salsa. Baby pattypan squash can be used in place of the zucchini or in addition to it. A wire cooling rack placed on top of the grill makes it easier to cook the tiny squash and prevents them from falling into the coals. Or use a grill basket.