Otherwise known as tasseography or 'reading the tea leaves'. Introduced into Europe only as recently as the 18th century, as tea drinking gained popularity in the West from its roots in China and India.
The ritual method is to use whole leaf tea in a pot without a filter, poured into a shallow-bowled cup and drunk whilst considering the question about to be posed. When the tea is drunk the querent swirls the cup three times clockwise and then empties it inot the saucer. The patterns made by the residual leaves, and their positions and clarity, affect the interpretation.