"Fab Food" should be considered the modern evolution of the 20th century "Fast Food", which originally arose with the rise of the automobile. Now, with the development of nanofabricators (specifically those which can produce food, Makers) food-prep time is at an all time low. However, in the Inner System, many forms of nanofabrication are restricted to the public or require significant investment to obtain in one's own home. Similarly, food and the resultant blueprints are treated as a protected IP by major hypercorps. This means there is a market for maker-produced food which can be whipped up on the spot, or is pre-fabbed waiting for assembly into a final meal to hand to a customer on the go - even if most modern transhumans walk or take public transit.
A typical fab food outlet can be as small as a bulky vending machine - with racks of food and drink to order, or big enough to walk in and form a line, or sit at a table for a quick meal. Most common though are kiosks or alcoves about the size of a traditional food stall/stand. Here you will see many familiar brands and styles, though the names have often changed as a result of rebranding, public pressure or loss of original rights. Groups like Golden-M, Burger Queen, Wendi's, White Palace, Stardoes, The Colonel's, Taco Toll, Pizza Shack, Little Kaiser's, Wyld Zings and School of Subs still exist and "license" official branding and food recipes in blueprint form to franchises. Local installations to match the local culture are also common.
The food seen in Fab Food shops has a little variety, but is built on a theme - it must be quick to make from simple ingredients which can be assembled in a fab and either shaped to form in it or by a quick intervention of a bot or robot waldo, then packaged to go for the customer. The largest and highest quality shops have the proper meat flash cloning in the back, but most kiosks can only have the maker assemble relevant protein strands and apply flavoring substitute. "Burgers" and other sandwich substitutes, processed meat nuggets or strips, chipped and fried vegetable fiber, kebabs, noodles, flatbread, and various other packagings of meat and grain form the underlying menu of most places - in some combination. Much of the selection depends on local tastes. With synthetic flavoring and a rough equivalent in components, most people claim the food at least tastes like historical fast food - but some of this could just be Earth nostalgia. Even so, despite what many see as a low quality, the food is highly convenient, and modern medicine will prevent or alleviate most problems of consuming too much. Drinks are also sold in fab food places - either mixed on the go in a maker, or premade in bulk by fabricators in cans or bulbs to be sold instantly and replaced over time.
Typical setup for a Fab Food shop crews it with one or two bots (Servitors usually) or just a remote waldo setup run by one or more infomorphs - assuming the type of food being served can't be completely replicated in the Maker. These workers move food around in prep units or place them in containers or may assemble several bits of food into a singular item. Occasionally, they interact with customers - but this is not required, transactions are digital and ordering can be done via apps on the mesh or in AR. Operating these systems may be simple AI though many places are wary of AIs operating anything related to nanofabrication - meaning indentured infomorphs are increasingly common - an extremely low paying contract. In places where economics allow it or force it, these may be remotely operated by people at home who lack other job skills; the young (often students) who lack skills and experience, former indentures with no real job market, ex-criminals and others with problems integrating in normal society. A new trend in "premium" Fab Food Shops has arisen as well, where the price and quality are slightly higher, but really the user is paying for a brief interaction with a real human contractor - not an indenture, who is present physically or as a cheery AR avatar - an attempt to cash in on some anti-indenture movements.
Fab Food is all over the Inner System in tightly packed cities, and spin gravity habs. Some also occur in highly populated beehives, though their menus might be a little altered by the requirement to work in micrograv. Extropian habs sometimes work with Fab Food, but are often blacklisted by major franchises due to their more open policy on IP - and their more open stance on personally-owned fabrication. One typically sees them clustered around major areas of transit, such as in sky or spaceports and train stations, or in long rows along major thoroughfares. They mix flashy physical lighting with bombardments of AR ads - some of which will even fight with other ads. These little kiosks are intermixed with "traditional" street food, actual people frying up noodles, or in little stalls with cages filled with live poultry - or tanks of seafood, or with the kebab grilling right in front of you. These "mom and pop" operations compete with major franchises and can stay in business because of their increased "authenticity" of food and charge slightly more, though the food can't be said to be as convenient.