Blood elf: They eat a grains and fruit, mainly for the rich and nobility. The lower class eat larger portions since they tend to be the working class, so they eat meat, most likely fish or Lynx, eggs, fruit, and a grain. Both tend to drink tea or nectar with their meals.
Draenei: They eat a lot of fish and fruit, mainly berries and using a mixture of both Draenor and Azeroth dishes. They drink milk and sometimes juice/nectar with their meals.
Dwarf: They go for more starch and hearty foods, so expect a lot of potatoes, mushrooms, fish, and bread with eggs and bacon. It’s tradition for Dwarves to start the day with Ale, but some have decided that coffee is just fine
Gnome: Gnomes are ever so busy, so they’ll get quick snacks and black coffee to tie them over.
Goblin: Goblins tend to eat a lot of junk. So they tend to eat things like Goblin-invented quick meals (imagine TV dinners) that aren’t as healthy as you might think. Other times they might use an invention to go fishing to get actual food, but they prefer their quick meals to go with their Kaja cola or fruity drinks.
Human: Depending on the household. A Human’s breakfast would vary from pancakes to the classic bacon and eggs. Humans like to have hearty meals with their coffee or tea.
Night elf: They are borderline omnivores. Some Night elves prefer a Vegetarian/vegan diet, others like to have meats. Night elves would have savory home cooked meals like Porriage, quiches or danishes. They like fish and tend to use home grown fruits and veggies for their meals. They are all for the herbal and the health beneficial teas
Pandaren: They have a banquet. They have fish dishes, stir-fry, noodles, you name it. They enjoy a nice cup of tea and ale.
Orc: Meat, meat and MORE meat! That is the Orcish diet. They aren’t too into fruits and veggies unless it is served with some kind of meat. An average Orc plate will have sausage, ham steaks, bacon, and eggs just for the heck of it. They might have an ale or two with their meal, because why not?
Tauren: They go for more of the vegetarian dishes. Some might eat eggs or even meat. But most Tauren prefer to go for a meatless diet. So they’ll eat fruits, grains, and vegetables and drink traditional herbal and spice tea.
Troll: Trolls, though in various tribes are known cannibals, have a similar diet to the Night elves. But they prefer meat. They’ll eat Boar, maybe even raptor or Scorpid. Sometimes they’ll have fish, and others times they’ll have just simple things such as eggs. Trolls don’t care what they drink with their breakfast. They might have tea or coffee, maybe even just water.
Undead: They don’t really need to eat, but for shiggles they’ll eat flesh or bugs. Maybe drink some embalming fluid for pure aesthetic.
Worgen: Much like humans, Worgen like hearty “old fashioned” breakfasts. Though for some, they may prefer meat over pancakes. Others go for scrambled or poached eggs with an array of proteins, like beans. They have tea, mainly herbal tea with their meals.