Two Indian restaurant chains are battling it out in court over claims to the dish’s origins.

Butter chicken — one of India’s best-known dishes globally — is delicious and apparently also contentious, with two Indian restaurant chains doing battle in court over claims to its origins.

The lawsuit — which has become a hot topic in India — was brought by the family behind Moti Mahal, a famed Delhi restaurant brand that has counted the late U.S. President Richard Nixon and India’s first prime minister, Jawaharlal Nehru, among its guests.

It claims restaurant founder, Kundan Lal Gujral, created the curry in the 1930s when the restaurant first opened in Peshawar before it moved to Delhi. In a 2,752-page court filing it has sued rival chain Daryaganj, accusing it of falsely claiming to have invented the dish as well as dal makhani, a popular lentil dish that is also laden with butter and cream.