Few experiences compare to dropping by North Beach's Maykadeh on a Saturday. It may seem like every Persian in the Bay Area has shown up, and the wait can be prohibitively daunting. Our advice: Make a reservation, go on a weeknight, or, if you must plunge into the fray, know that an hour spent twiddling your thumbs is a small price to pay for magnificent, saffron-marinated lamb kebabs and intensely flavored stews such as khoresht fesenjoon (chicken in a razor-sharp pomegranate-walnut sauce) or khoresht bademjan (a dinosaur-size lamb shank braised with saffron and eggplant). At nearly 20 years old, Maykadeh should be considered one of the great old-school ethnic restaurants in San Francisco. Or rather, it should be considered one of the great restaurants, period. Go there now.