I'm sure there must be something like this somewhere, but a search for "improved food" and some related permutations thereof didn't net me anything.
The idea is quite simple. We pool efforts to create a nested list of food types, organized to show what has vegetable, meat, etc. Toady has a lot on his plate, and the more scutwork we can take off his hands the sooner he can implement stuff. So if we compile the list, he can create the new class and datafields therein and use our ready-made listing to flesh things out, speeding up the process.
We'd end up with the potential for much more variety in foods, and a much more logical and sensible handling of them. If, for example, workshops-as-areas gets implemented, we can reasonably expect to have the cook prepare food on the fly for hungry dwarves. For dwarves on a break, maybe they pick up a cup of soup and a sandwich. At mealtimes throughout the day maybe they serve a roast side of meat on a table and let dwarves chip away at it, then at the end of the mealtime it gets brought back to the kitchen and preserved at a lessened quality and hungry dwarves in search of a midnight snack can grab a quick bite. If you want a 24-7 fortress, set up a rotation of cooks to keep the kitchens open all the time and fresh food constantly available. Also this would add the possibility of food wasteage.
Not to mention, nobles might demand a separate kitchen and/or fancier foods.
But I digress.
Easy---Sandwich
Bread + Meat = 2 sandwiches.
Easy---Salad
Plant + Dressing (Spices + Milk?) = 2 salads.
etc.
Edit: The perils of searching at 3am. =)