US-based quick service restaurant (QSR) chain Jack in the Box has broadened its menu with the introduction of the Smashed Jack burger.

The new offering is a quarter-pound smashed-inspired 100% seasoned beef patty with grilled onions, thick pickles and a novel Boss Sauce, all served on a brioche bun.

The new burger is available as a classic Smashed Jack, a Bacon Double Smashed Jack and as a combo meal.

The addition is part of the QSR chain's ongoing effort to enhance its burger selection and provide better-tasting options to its customers.

The Smashed Jack is now available at all Jack in the Box locations for under $10.

The QSR chain has also introduced other limited-time menu items including $3 Jack Wraps and the $20 Mega Munchies Box.

Customers can purchase these items across all Jack in the Box restaurants in the US, as well as through the Jack app and website, until 18 February 2024.

Jack in the Box chief marketing officer Ryan Ostrom said: “Smashed patties have been extremely popular, and our new Smashed Jack pays homage as its first fast food rendition while adding a unique Jack twist.

“Thanks to high-quality ingredients and a new chef-crafted sauce, our new burger boasts a bold, caramelised flavourful patty typically reserved for sit-down restaurants or homemade BBQ settings.

“We recognised an opportunity to lean into our innovation history and bring something new to the drive-through.”

In October 2023, Jack in the Box opened a new store in Louisville, Kentucky.