Food explicitly seen or named:
- Fish: salmon [lox], eel [bloodbane, unnamed yellow striped species, unnamed yellow mottled species], sturgeon, guppy, fish eggs, crab cakes (Breakneck Bog);
- Meat: yak [steaks, ribs], sheep, goats, chicken, wild boar;
- Fruit and vegetables: potatoes, cabbage, apples, lingenberries, dragon nip;
- Baked: bread [sandwiches], biscuits, poundcake, barley cake*;
- Meals: chowder;
- Other: eggs, dairy [yak, sheep, goat], honey, ice;
- Questionable: "sheep dip"**.
** "Sheep dip" is referenced in Fright of Passage, and may be mutton dripping or something similar.
In Book of Dragons, we also see Bork farming some sort of cereal, and later see him and his partner eating some sort of corn on the cob which... later pops. There's nothing that fits that description that I can find.
Animals which get referred to, may or may not be on Berk, may or may not be eaten:
- Squirrel [ref. Terrible Twos]
- Chipmunk [ref. Terrible Twos]
- Moose [ref. Dragon Flower]
- Shark [shark skin seen in The Heather Report and Cast Out Part 1]
- Ducks [ref. "leather duckies"]
- Squid (or giant squid) [ref. Dragon Flower, Frozen]
Stuff which may or may not be edible:
- Bark beetles [ref. View to a Skrill Part 2]
- Broad grass (presumably a species of broad-leaved grass?) [ref. The Flight Stuff]
- Fish oil [ref. Free Scauldy]
- Buckthorn, rock blossoms, goatweed, wild dagga plant [ref. The Eel Effect]
Addendum: other foods are also visible in the online game School of Dragons, although the canonicity of this game (and its grasp on geography) are questionable to say the least. Below is a list from the game.
Foods grown while farming:
- Dragon Nip
- "Toothache Plants"
- Black Beans
- Sheep (white or black)
- Brown Trout
- Ozark Cavefish
- Lugworm [bait]
- Glowworm [bait]
- Minnow [bait]
Other food items seen in quests [incomplete list]: