• Canape and cocktail recipes from this year's Birdcage marquees (includes the chicken sandwiches)

Simple, but oh so effective.

Since catering doyen Peter Rowland brought his chicken sandwiches to Flemington Racecourse for the first time in 1969, the white bread, mayonnaise-laden triangles have become the unofficial Melbourne Cup canape.

Peter Rowland Group expects to serve more than 20,000 chicken sandwich points at this year's Melbourne Cup carnival, enough to circle the track more than two-and-a-half times laid end-to-end.

So, after 50 years, what does the architect of the prolific sandwiches say has remained their number one feature?

"They're sloppy," said Rowland.

"That's the word I've instilled into the chefs. The stuff inside the sandwich must be sloppy. I want it to be sloppy."

Rowland's catering business, which has hosted some of Australia's most lavish parties for millionaires and billionaires, began in 1962 when he served his chicken sandwiches to Portsea beach-goers.

Rowland, 81, says his recipe hasn't changed since 1962. The full recipe remains secret, but we have some hints. First, the chicken.

"Most people roasted chicken and tried to make a sandwich out of it, but it was too dry. So we slowly poached them, just the breast."

Next, no crusts.

"Everyone used to do sandwiches with crusts on them, in those days. When I was eating, I hated the crusts of a sandwich."

Third, for peak "sloppiness", the butter, and homemade mayonnaise flecked with chopped chives and parsley, must fill the white bread right to the edge.

"The big secret was, and my tongue's not in my cheek, put double the amount of mayonnaise that you think you should. That was the big secret of the chicken sandwiches."

Rowland and his business have gone through a turbulent period in recent years.

In 2017 his company went into administration after an unsuccessful expansion into Canberra.

Rowland sold his $8.6 million Toorak mansion and paid his debts, with his company then morphing into the Peter Rowland Group funded and operated by Melbourne developer Mohan Du.

The reformed business aims more at commercial clients and expanded into Sydney's competitive catering market for the first time in April this year.

Yet the Melbourne Cup has remained a showpiece event for the caterer, dating back to when property developer and horse trainer Lloyd Williams first requested the sandwiches 50 years ago and "the Birdcage was just a big paddock with grass".

"Lloyd had chicken sandwiches, out the boot of the car, a couple of deck chairs. Maybe an umbrella, but they hadn't even invented market umbrellas in those days," he said.

Rowland has watched Birdcage food become more "ice carvings and prawns and caviar" than chicken sandwiches.

Some tents at this year's event, such as new arrival Bumble, have emphasised wellness and social awareness while the 1 Oliver Street marquee targets the "sober-curious".

Others, such as champagne producer Mumm which has replicated a Parisian boutique hotel with a concierge and secret VVIP room accessed via an "elevator", will not budge on opulence.

"The creativeness of the place now, I'm finding it difficult to see where it can go," Rowland said.

"There's some very good people doing very good functions, but do they run out of ideas? That's what worries me."

Why, then, does he think the simple chicken sandwich has remained popular among high-class Cup attendees for 50 years?

"It's fun. There's nothing serious about it, it's not up-itself."