Sooner or later, a vegetarian will show up at your cook-out, look into your carnivorous eyes, and ask to be fed. Don't be caught flat-footed as a host. This meatless menu preempts the politically correct and will have even the most unrepentant meat-eaters sniffing the air hungrily. First up, flame-seared Portobello Mushrooms topped with cheese, the vegetarian equivalent of a cheeseburger. Reminiscent of a grilled steak is ginger-studded Grilled Tofu. And finally, Steven presents a smoky, revamped version of an American classic, Macaroni and Cheese with Fire-Roasted Onions.