Orcs tend to eat smoked and "sweet" meats. They don't really have a concept for desserts, no floury cupcakes, no angel food, no wine. Their breads would probably be hard and similar to a flat bread, bread that doesn't rise.
Humans are incredibly curious in all walks of life. They will try anything once, seeing as there's plenty of human chefs that ask for you to bring them livers, spider legs, murloc eyes and anything else.
Dwarves tend to eat hearty meals. Haggis is a noted favorite, due to the cooking daily. They drink their ale, but we must remember, that everyone, everyone in WoW drinks ale with dinner. I do protest when there's so many people taking today's standards of alcohol and assuming that it was a bad thing in WoW. It's probably a lighter ale, or hell, even the water may have that touch. Do you have a water purifier? No? That's why you drink booze.
Night elves are noted to love ribs along with their kimchi. I could imagine that some of them love eating nothing but the greens, but nature loving doesn't mean they don't understand that a food chain exists. They are the top of the food chain, and they have no reason to fear showing it.
Trolls like rice, meat (raw or not), and whatever their hunters bring home. Seeing as the orcs steal rice from the trolls, I'm guessing orcs also now like rice.
Tauren seem to like things like mushrooms but I really imagine they also know they are top of the food chain. Sentient creature beats lower creature every time.
Worgen get the benefit of being people and feral beasts. So they eat from both worlds. Raw and cooked, spiced tasty things, to eating things just as they are.
There's other things out there, but this is my start.