Some like it hot, and here they are in heaven. Be forewarned: timid palates are ill-suited to the spicy Sichuan dishes that have made Z & Y a Chinatown favorite. Nearly every dish is crowned with chilies, from the huge mound of dried peppers that are tossed with tender, garlicky bites of fried chicken, to the toasty chili oil anointing slippery bean jelly noodles, buzzing with Sichuan peppercorn.The well-worn dining room may seem unremarkable and the service laid-back, but the cooking can be relied upon to hit its mark. Be warned that parking in the neighborhood is a tall order.