In ascending order of complexity:
1) Kitchen-made meals should require the ingredients be of different food types: ie. no more plump helmet roasts made of plump helmets, plump helmets, plump helmets, and plump helmets. This makes high-quality meals harder to make, and supports a diversified foodstream instead of a single-crop economy. Yays.
2) Meals should have numerous possible naming conventions chosen from a random list, possibly influenced by the ingredients (ie. the matgloss for an ingredient would suggest possible names, perhaps). Something made of plants might be a "salad" rather than a stew.
3) It would be nice if there was a way to get the kitchen to preserve seeds, bones, and shells if desired. I think it would be cool if there was an optional "prep" task done at a kitchen, extracting seeds, bones, and shells from things that had them, and increasing their quality by a small margin. Of course such things could be cooked with or without being prepped.
4) I've seen this one around in places: dwarves should get sick of eating or drinking the same thing all the time. If eating a food type they don't particularly like up to, say, 3 times in a row, they should start to suffer similarly to alcohol withdrawal. Or just get an unhappy thought. Of course, with enforced meal ingredient variation this is harder to get if you're preparing meals; a biscuit made from plump helmets and turtle would not count as the same as a biscuit made from plump helmet and dwarven syrup, even if they were both described as "plump helmet biscuits". Of course if they like the food, this shouldn't happen.
Cheers.