25 Union Square, Somerville. 617-623-7972. Peru's famous rotisserie chicken takes center stage at this casual grill. Sitting just around the corner from its more upscale sister restaurant, also dubbed Machu Picchu, the grill has its own simple draw: succulent, smoky-to-the-bone chicken roasted over real wood coals. Order a dinner plate or order it whole and this beer-marinated treat will likely leave you longing for more. But other hits dot the menu as well, including tasty tamales and Peru's giant corn Choclo Peruano, which you pluck from the cob and nibble with fresh farmers cheese. Fresh salads, some knockout sandwiches, and rich desserts round out the menu. Don't miss the el Peruanisimo, a truly inspired sandwich of roast pork and sweet potato perked up with slivers of aji amarillo pepper and vibrant lime-spiked salsa.