According to PerthNow, the upset neighbour wrote "PLEASE TAKE SERIOUSLY" on the front of the letter, which was written on behalf of their vegan family members.
The letter read: "Hello neighbour, could you please shut your side window when cooking? My family are vegan - we eat only plant-based foods - and the smell of the meat you cook makes us feel sick and upset. We would appreciate your understanding - thanks. Sarah, Wayne and kids."
However, the letter left various users dumbfounded by the request.
"I bet her mouth starts watering when old mate mows his lawn and she gets a whiff of that deliciously fresh cut gass but!" a Facebook user wrote.