CC Ādi 10.71

ei dui-ghare prabhu ekādaśī dine
viṣṇura naivedya māgi’ khāila āpane
ei dui-ghare — in these two houses; prabhu — the Lord; ekādaśī dine — on the Ekādaśī day; viṣṇura — of Lord Viṣṇu; naivedya — food offered to Lord Viṣṇu; māgi’ — begging; khāila — ate; āpane — personally.
In their two houses Lord Caitanya Mahāprabhu begged food on the Ekādaśī day and personally ate it.

The injunction to fast on Ekādaśī is especially meant for devotees; on Ekādaśī there are no restrictions regarding food that may be offered to the Lord. Lord Śrī Caitanya Mahāprabhu took the food of Lord Viṣṇu in His ecstasy as viṣṇu-tattva.