(1) The Book of Purification and its Sunnah
كتاب الطهارة وسننها
(65) Chapter: Ablution after (eating) that which has been changed by fire (i.e., cooked upon fire)
(65) باب الْوُضُوءِ مِمَّا غَيَّرَتِ النَّارُ
Sunan Ibn Majah 486 
It was narrated that 'Aishah said:
"The Messenger of Allah said: 'Perform ablution after (eating) that which has been changed by fire.'"
حَدَّثَنَا حَرْمَلَةُ بْنُ يَحْيَى، حَدَّثَنَا ابْنُ وَهْبٍ، أَنْبَأَنَا يُونُسُ بْنُ يَزِيدَ، عَنِ ابْنِ شِهَابٍ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، قَالَتْ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ ‏ "‏ تَوَضَّئُوا مِمَّا مَسَّتِ النَّارُ ‏"‏ ‏.‏
Grade :  Sahih (Darussalam)
Reference : Sunan Ibn Majah 486
In-book reference : Book 1, Hadith 220
English translation : Vol. 1, Book 1, Hadith 486