milk?!

if only my grandma would see that!
sbrinz is right, the greek one does come from fish eggs.
here is a quick translation from a greek recipe website. i have not tried it myself though, but it seems to be quite close to the real thing
200 gr cod roe (usually)
350 gr bread (not the crust) (different opionion about whether bread should be fresh or old)
1 onion
2 lemons
1 glass oil (normal glass water)
pepper
-----------------
1. moist the bread and drain it
2. in a blender, mix the fish roe and the onion. add pepper, bread and mix
3. slowly add oil and lemon
4. try out and add bread or oil if needed
recipe here:
http://www.sintagespareas.gr/sintages/taramosalata.html
some people add potatos. you need to mix everything quite well. some people also advice to use the blender for the fish roe alone at the beginning. some people also add garlic, but i doubt the original recipe calls for it.
i hope that helps!