Top restaurantes stock high-quality ingredients we as consumers simply cannot obtain...And whats more is they get them for a bargain (bulk orders etc).
Not only this, but restaurantes have utensils and kitchenware most households do not (im sure).
So a restaurant that offered groups and families
their own personal fully-loaded open-plan kitchen (surrounded by several other make-shift kitchens used by other customers) with access to all their ingredients allowing them to cook whatever they wanted really.
Thus eliminating the middle-man (supermarket and grocey store), not to mention the apect of not cleaning up the mess...aswell as the 'access all' cooking materials dynamic.
Customers would be charged according to what they use + taxes.
This type of service would not only be more simple that doing it at home, but for roughly the same price (or cheaper) as purchasing the goods yourself
All types of receipes could be available for the groups to view during the pre-cooking consultation, aswell as the option of having a proffessional trained chef readily available for assistance at any time (for an additional fee of course!) as well as the optional servants waiting on the tables.
This type of service would appeal to markets who pride themselves on home food, or simply just wanna break-bread out with family and/or friends, for not so much $ and a little bit of novelty.