I have a small idea myself due to all these thoughts.
What if there was different workshop kitchens. Like...
Small kitchen: 1x1, Can make only "Hot meals". To be used by dwarves in rooms. Mainly stews (think of it as a small pot over fire). Can be translated over to adventure mode as well. This one makes less sense in dwarf fort mode though. Maybe instead it could be be used by military personal, to make their own meals on patrol.
Better equipped: 2x2 or 3x3: Able to make cold meals, longer lasting meals and such. This is what would use preserved foods, able to make either hot meals, or longer lasting preserved/package meals for storage and eating on the go such as military, or for dwarves to carry on their person. (Such as the day that dwarves can eat outside of the storage area, or dining room)
Preserving room: (Insert better name here) able to preserve food, either by adding salt to food types, canning (if allowed) Freezing (requires ice blocks, or sub normal temperature rooms, either by adding alot of ice, or eventual adding of colder cave systems) and the like.
Communal kitchen: 5x5 or 5x2, the sort that one would expect to be a "cafeteria" sort, with a stock of dwarves making food for hungry dwarves to eat without needing crappy cooks. Several cooks would stock the area, ready to take orders and give out meals. Able to make large "potluck" sort of large stews in huge canisters that can last sometime, and is able to stay stocked for when all your cooks decide to go !!Urist McCook!! or some other issue.
I've salvaged these from a few topics, but didn't see em on here. A few might be bad idea's, but it's some idea's anyways.