This dish is particularly delicious in summer, when zucchini, peppers, and summer squash are farm-fresh. You can also pile the grilled vegetables onto crusty French bread that's been slathered in creamy chevre. Or make hors d'oeuvres by topping Crostini with slices of grilled vegetable and some crumbled chevre. The vegetables can be grilled up to 1 hour in advance; assemble just before serving.