Mr De Bellis hails from kitchens as prestigious as El Bulli, having worked at the famous Spanish restaurant in 2008.

Until its closure in 2011, El Bulli was known for its molecular gastronomy.

"It was brutal but super exciting," Mr De Bellis recalled.

"You work 16 hours a day and spend the rest talking to other chefs.

"I spent six months like this - I was a little bit thinner."

The experience working with head chef Ferran Adria and chefs from across the world helped him launch his career as a pastry chef.

He started Pasticceria De Bellis in Rome, in partnership with his brother, and said salted caramel remained his favourite flavour.

"It's not the technique you pick up, because you can read a book, it's a mentality," he said.

"What's an egg? How can you use all the parts for different things?"

A lifelong passion for gelato led him to be a consultant for equipment brand Carpigiani and then a meeting with Orange's Sarah Quigley and Andrew Hamilton.

The pair, wanting to start a gelateria, visited Bologna to learn how to make gelato and the trio hit it off.

"I usually don't accept invitations from students to go out because they just want to talk about gelato, but we had a wonderful night out," Mr De Bellis said.

"They asked me to come here and I've been helping them make it as smooth as possible."

Spilk Milk Bar has been under construction in Sale Street since the beginning of the year and is expected to open to the public at the end of the month.

When the Central Western Daily visited the store on Friday, Mr De Bellis and Ms Quigley were working with a batch, discussing temperatures and honing the result.

Once open, it will serve every flavour from blood orange and pear, to coffee and vegan-friendly dark chocolate.

"She's doing a very good job, she's looking for the small details," Mr De Bellis said of his pupil.

Mr Hamilton said he had enjoyed working with the Italian chef, particularly because different milk behaved in different ways.

"It's a science," he said.