Blood - Dwarves should be able to use blood as an ingredient when cooking. Very dwarfy!
Blood sausage! Black pudding is a delicious and essential way to use up blood. If we're having this though, we should have two other things;
Butchering should involve hanging the kill, firstly to drain the blood and secondly to allow meat to mature - certain meats, especially game, are much more palatable if they are hung for a few days.
Religious diets. Dwarves that follow certain Gods should refuse to eat food contaminated with things that are the dwarfy equivalent of non-kosher or non-halal. So a religious dwarf may refuse to eat blood sausage if their god does not allow blood consumption. Another may insist on consuming blood for their God. How far they are willing to go (ie, to starvation and death) should depend on strength of faith. A fairly religious dwarf who eats a forbidden food rather than starve should get a negative mood because of it.
Storage and Preservation...
Yes, yes and yes! In medieval times, if you weren't able to find some way to extend the shelf life of food you starved. Smoking meat, drying vegetables, storing in oil or fat, salting... these are all simple, basic preservation techniques that we have used since before we even had a recorded history. In that vein...
SUBSISTENCE FOODSA dwarven caravan that embarks and runs out of food should not risk starvation unless it eats vermin, but should have to work harder. Humans used to consume things like acorns; unpalatable and technically inedible, but if you roast the acorns, crush them, pour the crush acorn pulp into a cloth bag and let it sit in a current of water such as a stream for a day or two until the tannin is washed out, you can then mix it with a little honey, or water, or milk and heat it to make a sort of acorn porridge/mash.
Although... preserved foods are not fuel-less. Making jam, chutney or canning and preserving food requires cooking. You don't know how bad vinegar is until you're forced out of the house while a pot of onion and chilli chutney on the hob fills the house with eye-stinging vinegar steam.
Communal Cooking - Hot meals prepared by cooks to be ready-to-eat at a communal serving area. When a dwarf gets hungry, they come to the dining hall and take a serving of "the meal of the day". Players could keep this area stocked with meals using the Make Hot Meal option. The meal queue would be reduced by dwarves taking meals from it and spoilage. When the economy kicks in, this could expand to the Tavern concept.
We will need dwarves to either make meals much slower to prevent overcooking and wastage, or make dorfs use "leftovers" to make a low-quality but nutritious meal such as bubble and squeak. In fact, dorfs should automatically prefer to include meal leftovers in cooking if there are any before using fresh ingredients. So bubble and squeak, soups made from leftover roasts, curries made from cold meats, bread and butter pudding, bread soups...
It might actually be easier to have, instead of a kitchen workshop, more of a canteen. Dorf cooks serve up dishes to order and remain in the canteen workshop continuously, leaving only at need. A badly managed fortress could cause bad moods when there are no dorfs set to cook currently at work in the canteen, resulting in dorfs either going hungry or making a makeshift meal (ir, making a quick sandwich and grabbing a plate of cold leftovers instead od getting a fresh dinner). Fortress could have an option for "all dorfs cook" or "only chefs cook", so that people who like to make less workhouse style fortresses can still have options for them.
Dorf Families. Dorf families should eat together - go to the canteen at the same time and, where food hall layout and crowding allows, should sit adjacent to each other to eat. Unless Toady brings in some sort of schooling option, in which case all dorf childen should be taken to the canteen at the same time by whatever dorf adult is in charge of them to eat together.