MCDONALD’S customers have been ordering their own special off-menu items for years, but now one of their most popular “secret” burgers has arrived on the official menu.

McDonald’s is temporarily selling two of their most regularly requested items — the Chicken Big Mac and Shaker Fries.

The Chicken Big Mac is exactly the same as the original Big Mac, except you get two chicken patties in place of the beef ones. And yes, the famous Big Mac special sauce is included.

The Shaker Fries were introduced in 2011 and faded off the menu, but now they’re back. They’re basically a bag of regular French fries that come with a sachet of cheeseburger flavouring. You mix the sachet into the bag of fries, shake all the flavour around and then you get cheeseburger-tasting chips.

“The iconic Big Mac and the McChicken are among our most popular burgers, so it made sense to mix up these two classics and give our customers a new and exciting product to try — the Chicken Big Mac,” said McDonald’s Australia’s CMO Jenni Dill.

The Chicken Big Mac and Cheeseburger Shaker Fries will be available in all McDonald’s restaurants around the country from today until July 18.

McDonald’s has been changing up its menu recently to remain relevant in an increasingly competitive takeaway food sector. Both here and overseas, it’s been struggling to thrive in a market where consumers are looking to healthier, more gourmet options.

According to a 2014 Euromonitor report, the fast-food sector in Australia grew at a slower rate than expected. Compared with a general growth rate of 5 per cent across the Australian food service industry, takeaway food grew at only 2 per cent.

The rise of food delivery services such as Uber Eats and Deliveroo means fancier takeaway options are now easier for consumers to get their hands on.

In recent years McDonald’s has introduced several new gourmet burgers, including the Create Your Own Taste and Gourmet Creations ranges, as well as more wraps and salad options.