A really hot cup of tea (hence the name) served by the road-side teastalls found in every major...scratch that...EVERY city/town/village in India.
Originally made popular by the good residents of Bombay looking for their morning refreshment before catching the first local to their daily wages.
Man to guy at the tea stall: Bhaai, ek chai. (One cup of tea, please.) Bilkul cutting dene ka. (Its gotta be cutting!)
Boy hawking tea at the station: Idhar milega idhar! Bilkul cutting chai! (Get it here! Cutting chai!)