A Proper Chicago Dog

I may not be a fan of their pizza, but Chi-town knows their hot dogs. Where to get one proper in SF? Check out the cart in the corner of 7th and Folsom. Hours are sporadic, but the wares are authentic: Vienna beef, neon relish, pickle, celery salt, sport pepper, tomatoes.... I haven't tried their Italian beef, which I only discovered on their menu today, but trust I will!