The acquisition sees the three-strong group - which has sites in Winchester, Fareham, and Sheffield - significantly expand its size and geographical reach, especially in the South West where The Stable was founded and has a strong presence.
The sites included in the deal are located in Bath, Birmingham, Bournemouth, Bridport, Bristol, Cardiff, Exeter, Falmouth, Newquay, Plymouth, Southampton and Winchester.
The Stable's Kew Bridge and Cheltenham are not included in the deal, which was privately funded by Three Joes shareholders.
A decision on whether The Stable sites acquired will be re-branded as Three Joes has yet to be made.
“We’ve been huge fans of The Stable since we launched Three Joes in 2017 and this acquisition represents a significant step forward for us," says Three Joes' chief executive and co-founder Tim Hall.
"The Stable is five times our size and whilst we are all operating in uncertain times we are confident the business has a strong future ahead."
Three Joes was founded in 2017 by Hall, the founder of healthy fast food chain pod; Peter Bruton, ex-founder of Byron; and Emma Blackmore, an ex-Pizza Express and Pret menu development and procurement specialist.
The Stable was started in Bridport by Richard Cooper and Nikki Cooper in 2009. Fuller’s acquired a 51% stake in the then six-strong business in June 2014 for £7.3m.
It subsequently acquired a further circa 24% and then in June 2018 Fuller’s completed the acquisition of the remaining circa 24% stake of The Stable, where at that point it had grown to 17 sites.