The world has met Erin Patterson as the murderous cook behind a mushroom meal that killed three relatives. But years before her courtroom infamy, the woman from Melbourne's suburbs divided opinions.

An alleged murderer testifying as a witness in their own defence is a rare strategy and normally a last resort.

The 50-year-old's in-laws died in 2023 after eating beef Wellingtons prepared by Patterson - they were later found to contain toxic mushrooms.