Netizens from the two Southeast Asian nations -- including the Malaysian prime minister -- put aside a longstanding culinary dispute about the origins of the slow-cooked coconut curry to express outrage at the cluelessness of the British show's judges.
Judge Gregg Wallace and co-judge John Torode sparked a storm this week by criticising Malaysia-born contestant Zaleha Kadir Olpin's dish because the "chicken skin isn't crispy, it can't be eaten".
Rendang, which originates from West Sumatra in Indonesia, is usually chicken or beef slow cooked in spices and coconut milk for hours and is not crispy.
Olpin served her chicken rendang to accompany Nasi Lemak, a popular aromatic rice dish from Malaysia.
Hundreds of people took to social media to point out the judges' amateur mistake.
In Malaysian cyberspace, a Facebook page "Justice for Chicken Rendang" was set up collecting signatures for a petition demanding an apology from chefs Wallace and Torode.
"As a Malaysian, if I could, I would personally go to the show and rendang their head. Uncultured swine, doesn't know variety of cuisine and claims to be Masterchef?" wrote Facebook user Jin Wee on the page of Malaysian newspaper The Star.
As controversy grew online, Malaysian Prime Minister Najib Razak waded into the debate, saying: "Who eats 'crispy' chicken rendang?"
The British High Commissioner to Malaysia, Vicki Treadell -- who was born in Malaysia -- also tweeted at the embattled judges.
. @MasterChefUK@JohnTorode1 & @GregAWallace#Rendang is an iconic #Malaysian national dish not to be confused with Indonesian options— VickiTreadell (@VickiTreadell) April 3, 2018
It can be #chicken#lamb or #beef
It is never #crispy & should also not be confused with the#friedchicken sometimes served with #nasilemakhttps://t.co/3sCBsgiwgQ
"Rendang is an iconic Malaysian national dish ... It is never crispy & should also not be confused with the fried chicken," she wrote on Twitter.
In response, Torode told his online followers: "Maybe Rendang is Indonesian!! Love this !! Brilliant how excited you are all getting .. Namaste."
Maybe Rendang is Indonesian !! Love this !! Brilliant how excited you are all getting .. Namaste https://t.co/CThRmhaEAc— John Torode (@JohnTorode1) April 2, 2018
But his response did little to douse the social media flames, with many users pointing out that "namaste" is a greeting used in India.
Despite sometimes rocky relations, neighbours Indonesia and Malaysia share an intertwined history and share a number of cultural and culinary traditions.
Rendang is a popular dish in both countries and its origins are sometimes claimed by Malaysia. Click for more trending news