The proposals, which involve a move to turnover-based rents, was approved by 90% of creditors in a vote last week.
First mooted last month, the CVA was previously reported to be focused on dealing with ongoing uncertainties created by the pandemic, and providing a platform for Leon to return to its previous positive trajectory.
Quantuma advised on the CVA, with the firm’s Andrew Andronikou and Brian Burke now acting as joint supervisors to oversee the process.
Andrew Andronikou, managing director at Quantuma, said: “Given the struggles of the retail and casual dining sectors as a result of the pandemic, and being in the run up to Christmas, securing 670 jobs at Leon is a real positive to end the year.
"We are pleased that the majority of creditors have supported the proposals, which will enable us to work with the business as it recovers and provide a strong foundation from which it can return to the strong growing business it was in 2019.
“The CVA has been structured in a way to support Leon while it continues to be affected by reduced footfall and the ongoing uncertainties as measures continue to be deployed to deal with the covid-19 pandemic, whilst delivering the best possible outcome for creditors.”
Leon operates 75 sites globally, both owned and franchised, including 44 corporate stores in the UK.
In the year to 30 December 2019, Leon achieved revenues of £76.3m and planned to open 30 new restaurants in 2020.
The impact of the pandemic saw a significant reduction in sales, as footfall from city centre workers and domestic and international tourists all but disappeared.
John Vincent, founder and CEO of Leon, added: “I would like to thank all the landlords and everyone else who has supported us through this process. This gives us the platform to rebuild Leon and return it to growth.”