A popular Australian chef whose beef wellington recipe was the basis for convicted killer Erin Patterson’s deadly lunch says the situation is “upsetting” and has asked for privacy.

Patterson, 50, was convicted of three counts of murder and one count of attempted murder on Monday, after she served beef wellington laced with death cap mushrooms for lunch at her Leongatha home in July 2023.

It was revealed during her trial the recipe she had based the meal on was from Nagi Maehashi’s cookbook titled Dinner.

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Maehashi is the chef behind the popular website RecipeTin Eats.

Photos released by the Supreme Court of Victoria following Patterson’s guilty verdict show Maehashi’s cookbook in the killer’s home.

Maehashi pleaded to not be questioned about Patterson’s case in a statement posted to Instagram on Tuesday.

“It is of course upsetting to learn that one of my recipes — possibly the one I’ve spent more hours perfecting than any other, something I created to bring joy and happiness — is entangled in a tragic situation,” she said.

“Other than that, I have nothing to say and I won’t be talking to anyone.

“Thank you for respecting my privacy.”

Maehashi’s recipe directed the beef wellington be cooked into a log, however, Patterson claimed she made individual serves as she could not find the right cut of beef.

Photos were taken during examinations of the lunch leftovers, which were subjected to various scientific tests.

Toxicology reports found the leftovers contained death cap mushrooms, while the fungi was not detected in plant virology and microscopy analysis.

Patterson was found guilty of the three poisoning murders of her former in-laws Don and Gail Patterson, both 70, and Gail’s sister Heather Wilkinson, 66.

She was also found guilty of the attempted murder of Wilkinson’s husband, Ian, 68.

Reports surfaced on Wednesday morning that Patterson was going to appeal against her conviction, however it’s unclear exactly what grounds the appeal will be on.

Her legal team will have 28 days from the date she is sentenced to file an appeal. She will be sentenced later this year.