The Trispan-backed chain has four new locations in the pipeline, all of which are expected to open before the end of the year.
It comes as Thunderbird announces the appointment of Nick Moule as its new head of operations.
Moule previously held senior roles in Mitchells & Butlers and more recently Stonegate, where he headed up the Common Room and Sports Bar & Grill.
“Having got to know the brand over the past few months, I am very excited to be joining Thunderbird and becoming part of an amazing team," he says.
Last month Thunderbird opened its fourth bricks and mortar location in Earls Court, which was used as a platform to launch a revamped brand identity that moved away from its street food, QSR roots and reframed it as a more fast-casual, evening-friendly proposition.
He said: "I came on board 14 months ago, and it had lost its way a bit, it hadn’t really had the leadership, and the branding wasn’t quite right.
“Bringing street food onto the high street is not an easy change to make, but we’ve spent the last year honing it and getting it in line with how we wanted it.
“It is Thunderbird version 2.0, the relaunch. It will be the first one that will show the new look and feel of the brand and our direction going forward.”
Thunderbird's restaurant portfolio currently includes sites in Charing Cross and The O2, as well as a unit at Pergola Paddington.
In February last year, prior to the onset of the Coronavirus pandemic, the group closed its original bricks and mortar restaurant in Brixton, with Trispan operating partner Robin Rowland describing Thunderbird at the time as a 'work in progress'