As soon as you open the door of the Midwest Grill, the aroma of garlic and meat starts your mouth watering. Distractions abound: personable waiters, lively music, the salad bar-like selection of side dishes (superb potatoes, black-bean stew, salads, olives, and rice). But you can't ignore the scent of meat juices dripping onto an open fire. Finally, here come the waiters, bearing the long, swordlike skewers of meat that make up rodizio, or Brazilian barbecue. They slice off portions of perfectly grilled pork, lamb, or beef, as you help with salad tongs. They return with linguica sausage, chicken, and even chicken hearts. Take a break and check out the gregarious families, voracious students, and other carnivores around you, then flag down a circulating waiter and dig in again.