Well, what about a possibility that the food is generated/synthesized
inside the unit? Rather than elsewhere and delivered either via transporter or dumbwaiter or mini-turbolift? Have we explored this as a possibility? Each unit could feed from a matter tank nearby that's regularly replenished from a larger tank.
Anyway, here's how I envision my TMP/TWOK-era food synthesizer working, at least from the user experience
Upon approaching the synthesizer unit, the crewmember can see a menu selection on the left, with menu display controls off center to the right, and the selection panel to the far right.
By default, the menu displays the most popular menu options. These are but a small selection of hundreds of dishes from across the Federation.
This menu listing can change by using the Menu Display control to the right:

The possible choices are: Full Menu, Popular Menu, Appetizer Menu, Dessert Menu, and Beverage Menu. Each of these will prompt the user to issue codes to sort by a variety of ways:
- Full: Culture, Protein, Alphabetical
- Popular: Culture, Protein, Course, Alphabetical
- Appetizer: Culture, Protein, Alphabetical
- Dessert: Culture, Alphabetical
- Beverages: Culture, Non-Alcoholic, Alcoholic, Alphabetical
The "Selection" Panel includes a viewing screen, which shows the "Services" department logo by default.
The keypad allows the user, at any time, to enter in the 4 digit code of any item, which will display an image of the selected item on the viewing screen. The user can use the left and right arrows to scroll through information about the menu item, such as a brief history of the dish and nutritional information. When an item is not currently selected, the user can use the left and right arrow keys to cycle the pages of the displayed menu listing.
To add a selected item to the user's order, the "Add" button is pressed. To remove an item from the order, the "Delete" button is pressed. To clear the entire order, the "Clear" button is pressed. There are limitations to a given order: they cannot total more than four items, but within that, they cannot contain more than one main dish, more than two appetizers, more than 3 desserts, or more than 4 beverages. If an user would like more items, additional orders must be placed after each order is synthesized.
To confirm the order, the "Confirm" button is pressed. The user is then prompted, via the viewing screen, to either press the "Deliver" button to begin the synthesis process of their order immediately, or enter a time delay if they'd like their order to begin synthesizing at a later time. In the latter case, the user will be given a 5 digit code if they wish to edit, deliver, or cancel their order before the given time. A queued order is then stored into the memory banks of the synthesizer and will begin processing at the appropriate time.
Once the "Deliver" button is pressed or the given time is reached, the unit begins synthesizing the order in whichever slot is currently available.

The "Delivery Status" indicator below each slot has a row of colored indicator lights, each which light up to display the current status of the slot:
(NOTE: I'd originally remembered the TOS food slot's indicator lights lighting up from right to left, which is why I chose the ordering of the indicator lights above, as an homage. Upon checking this morning, I confirmed I misremembered, so I will be re-ordering these indicators to flow from left to right, as seen below)
- Awaiting Selection: the orange indicator light shows that the slot is currently idle and is not synthesizing any foods
- Selection Processing: the yellow indicator light blinks to show that the slot is currently synthesizing an order. Depending upon the complexity of the order, this process can take anywhere from three to thirty seconds.
- Selection Ready: the green indicator light shows that the order is ready to be retrieved by the user. The slot door slides upward so that the order can be retrieved. If the order is not retrieved within one minute, the door closes and the order is broken down into its base elements which are then available to be synthesized for other orders.
- Disposal Mode: the purple indicator light shows the slot is in "Disposal Mode". When the user presses the "Disposal" button on the selection panel above, this indicator lights up on any available slot. The slot's door opens, allowing the user a one-minute window to return any trays, dinnerware, trash, or discarded food to be broken down by the system and resynthesized later.
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Obviously, I put a lot of thought into this! Let me know if anything stands out as a huge oversight by me, or if you see any misspellings.
I won't be programming these units to function in all these ways, of course, but I just thought it would be fun to approach this from an actual user experience standpoint rather than just throw random graphics or text on the display without any thought.
But I
will treat this
like I did my TOS food slots: when the player activates the panel, it will "synthesize" a random meal from about 5-10 meals I'll actually model, and I'll make sure the indicators light up as described above and all that. This is something I'll get to once I actually model the stuff.
I purposefully chose the unit
not to operate by voice command, because it further helps differentiate this unit from the refined tech of replicators we see in TNG. And, manual physical input still seems more common from a 2270s/80s (and 1970s/80s) standpoint.
And yes, as others have noted, the bulk of the menu options listed above are from MSGTTE. I also added a few more to "fill out" each column, either from my own brain or additional Andorian or Vulcan items listed on Memory Alpha.
@Redfern, good idea about the Caitain menu! I may add in that line just as an in-joke, if I can make it fit

. I
will not be programming the menu to actually list hundreds or thousands of food items, and I specifically chose the "Popular Menu" so that I'd only have to come up with one static list big enough to fill the screen
