It's named directly after the last Nizam of Hyderabad, Mir Osman Ali Khan, who reportedly asked his royal kitchens to invent a biscuit that was sweet and salty at once — an unusual combination that kept his name attached to the recipe ever since.
A dough of flour, milk, ghee, cardamom, sugar, and a pinch of salt is baked into a soft, crumbly biscuit that dissolves almost the moment it's dunked. Hyderabad's Irani cafés sell it by the piece as the standard accompaniment to a glass of Irani chai.