The new Wahaca in One New Change shopping centre in London's St Paul's is set to open on 3 October.
The 130-cover restaurant will be the first Wahaca to take reservations, and will sit on the first floor of the Cheapside development.
The company said it also had plans to make the restaurant its most sustainable to date, wth 100% of the waste from the construction being diverted from landfill.
The group, which was voted ‘Sustainable Restaurant Group of the Year' for the second year running, has also ensured that the new site will benefit from several energy management techniques such as waste heat from freezers being used to heat the restaurant's hot water.
Co-founder Thomasina Miers said: "We are very much looking forward to bringing Wahaca to The City and spicing up the food offer in the area.
The new restaurant will be open from 12 noon to 11pm on Monday to Saturday, and 12 noon to 10.30pm on Sunday.