Umm Salamah Radiyallahu ‘Anha says “I presented a roasted side portion of meat to Rasulullah Sallallahu ‘Alayhi Wasallam. He ate it and (thereafter) performed salaah, without performing wudu”.
It is found in some ahaadith that things cooked on fire nullifies the wudhu. This was also the madh-hab of the ‘ulama mutaqaddimeen. The madh-hab of the Khulafaa-rashideen, the four imaams and the majority of the Ulema is that those ahaadeeth wherein the necessity of Wudu is mentioned has been abrogated. This hadith of Sayyiditina Umm Salamah Radiyallahu ‘Anha also supports the madh-hab of the majority that Sayyidina Rasulullah Sallallahu ‘Alayhi Wasallam did not perform wudhu again (after eating the cooked meat) before salaah.