Altmer: Mustard
They're yellow, mustard's yellow. Sort of hard to stand if it's just a bunch of one or the other. If you eat lots of mustard by itself or go into a room with just Altmer in it, you're in for a pretty bad time. There's a bit (but not too much) of white wine in the good kinds of both.
Imperials: Ketchup
Your "bread-and-butter" if you will. Not the first, but they go on everything. During the Middle Dawn, after the Marukhati Selectives danced on the tower, Cyrodiil became an "empire across the stars." Similarly, you have to hit the bottle at just the right angle and just the right amount to get good results out of ketchup.
Orcs: Hamburger Relish
I would like to go with regular relish for the green=green comparison that, at its surface, seems so inviting. It's too superficial, though. Perhaps the original Trinimac-worshippers could have been such a relish, and truly a good companion to the mustard-folk, but they have been tainted. Hamburger relish reminds me a bit of poop. It's the same colour as Ketchup, which hints nicely at the newly-forged relationship between the Orcs and the Imperials.
Khajiit: Table Syrup
They both come in many containers and most importantly [the rest of Khajiits=Table Syrup]
Dunmer: Worcestershire Sauce
They're a mish-mash of good stuff. There's something fishy about them. They were invented in 1837. They were bought out by the people who own Ketchup a little while ago, which changed their distribution but not the basic ingredients. Hard-to-pronounce-ness is associated with these two things.
Bosmer: Vinegar
Mohammed Ali to the Khajiit's foot powder, which is a bad comparison for many reasons. They are sour and will eat you slowly if you surround yourself with them. Better than ketchup if you want to eat some fries. Also, [whizz].
Redguards: Whipped Cream
Speaks for itself. The sinking of Yokuda is like when you put ordinary cream into a whipping machine/whipper. Things just got shook up, and then [penguin ballet?]! Pirates. Whipped cream is always put on the dessert last, like how the Redguards got to Tamriel last.
Argonians: Pepper
Pepper is not a condiment. It makes you sneeze and sometimes [allegedly] poisons the entire southern half of your continent.
That's all I've got so far. Does anyone think anything should be changed?