A highly-respected specialist in both facial plastic surgery and ear, nose and throat surgery, Dr Zacharia was also the son-in-law of one of Trisha's neighbours, which is how the two met. "I wanted to paint someone who gave of themselves in the world," Trisha said.
"He came back to me and said he'd be honoured." Despite her initial intention to capture Dr Zacharia clothed in scrubs and at work in the operating theatre, Trisha admitted she changed her mind after meeting him and seeing his other qualities.
"He was such a gentle person," she said. "I wanted to paint more Michael the man, husband, father and friend." With her subject so busy with work commitments, it was hard for Trisha to catch up with him to do the necessary preparation that preceded the painting.
This meant it was completed in a demanding six-week period between February and March, which, although intense, suited Trisha, who admitted she worked better 'under the pump'.
I wanted to enter it because it's challenging and pushes your boundaries as an artist.
Originally intended to be done in oil-based paint, she decided to switch to acrylic paint because of the looming deadline (entries for the competition close on April 5) and used both a pallet knife and a brush.
And despite the short time frame it was completed in, she said she was more than pleased with how it turned out. "I feel as if I've captured that gentle and caring side of him full of soft magenta and lemon light," she said. "Then the shades of orange and green on the left represent his sharp intellect."
With judges only selecting 40 paintings to be exhibited from the 1,000 or so entries, Trisha wasn't putting any pressure on herself going into the competition.
But she did admit it would a great achievement to win or be chosen as a finalist. "It'd be fantastic," she said. "It'd be just another piece of the journey of life."
The winner of the Archibald Prize will be announced on May 10 and will receive $100,000.