Modern restaurants are commonly using an open kitchen area, however this breaches the compartmentation between the kitchen and dining area.

What are the regulations around doing this and how is it acceptable?

Are there certain measures a restaurant has to take to negate the increased risk of doing this?

Under Building Regulations they are not a place of special fire risk requiring enclosure, so can be in the same compartment as the dining area as long as the area has sufficient exits and, where necessary, protected routes, not going through or past the open kitchen. Whilst irritatingly not mandatory (like they are in the US) the provision of a fixed suppression system is also a common control measure for both open and closed kitchens.

Thanks

Any particular guide that you know of that has direct mention of open kitchens. I've struggled to find one?

https://www.riscauthority.co.uk/free-document-library/RISCAuthority-Library_detail.rc16b-recommendations-for-fire-safety-in-commercial-kitchens.html

Aimed at the insurance/property protection side of things not life safety so goes beyond what is in Building Regulations and similar guidance which are only life safety oriented. It, not unsurprisingly, prefers enclosure but does reference mitigation measures for kitchens that aren't enclosed (mainly supression)