This is how I would test the CCC cars on the City of New Orleans and the Texas Eagle....
Model the whole thing like a "Fast Casual" restaurant operation (Panera Bread, Pei Wei, Noodles & Co. etc.). Passengers line up at the counter and order and pay right at the counter. All items that do not need to be prepared (drinks, some side items, etc.) are given to the passengers at the counter, and also a number is given, they are asked to have a seat and then the food is brought to them. Most likely, the passengers would still need to be seated by a crew member so that tables are used appropriately in the small space.
The menus would be more of a Panera style... obviously not as large of a menu, but lunch would be more sandwiches, salads, soups, and then dinner would be entree salads, plus some pasta dishes. No cooked to order steaks, or fancy dinners. Just more basics. Breakfast could stay pretty close to the same since those items move out pretty fast already.
Would it be a complete disaster? I don't know.. but that seems to be how the car is set up... passengers could also take meals to go from the counter and go back to their seats. Something that many passengers would like to do, but is sometimes discouraged, and certainly not advertised by most train crews.
I think if the crews would actually give it a try.. this could work very well on SOME trains. It would also be, IMHO a better use of a 3 person staff... 1 cook, 1 LSA who actually has to take orders and work (there are some great LSA's out there but we have all seen the ones who just sit there doing nothing) and 1 food server who simply seats passengers, and brings the food to the table, and then cleans the table. No tablecloths, or place settings to deal with.
The name "Cross Country Cafe" seems to imply this type of service anyways...