As someone who played Runescape and designed a Necromancer Cook specifically because of that, I am prepared!
The Culinaromancer’s tools of trade are the tools of the magic, a component pouch of ingredients that are specially crafted over years of hard work and diligence to the craft of magic.
Animate Dead using the skeleton of a freshly finished meal, imbuing into it the seasoned anger at how the nobles dared to salt it! Send that chicken after them for revenge! (While I am aware that animate dead specifically says humanoid, I had asked and my DM had permitted it, and also you are writing a story like you said so it works). Your master chef uses one of those old styled seasoning wands, a little cannister on a handle that you dust the special bone dust and seasoning that your magical craft is fueled by, forming the entity.
If you want to purely have it be D&D related, the Abyssal Chicken familiar would be perfect as the familiar of choice, tasting like a chicken but having the truly delectable presence of the Hellish realms behind it’s beak. Truly a master chef’s ultimate familiar signifying the willingness to dive to the harshest worlds for the best ingredients.
For some fun flavoring of spells, Toll the Dead as a cantrip, but it is the dinner bell being heard that echoes into the soul, reminding them that they are the meal tonight. The trusty cleaver brought out and cooked with the burning green fire to cook the meat as it carves it from the bone, a beautiful flavor! False Life is powered by alcohol, the seasoning that you spritz over the meal that empowers you with the strength to go further on. A dried pepper is brought out and added to the delectable meal as you breathe Dragon’s Breath, applying a dragon’s touch to the meal. Want to ask the dead how they want to be cooked? Sprinkle some of your graveyard dirt and basil blend before igniting it, letting the lovely aroma that only the dead can bring flavor the corpse as they can speak what they want to be cooked as for your people. Perhaps you want to make a creature be dead before preparing the feast, so that in the middle it returns to life before dying once more, letting the fear of sudden death add that delicious final seasoning, a truly delectable final meal! And of course, if worst comes to worst, feel free to grab your trusty chicken’s heart you keep on hand for adding that bit of flavor of dinosaur blood, and bring a nightmarish fear of being cooked poorly to these wretched souls who dare get in the way of your meal.