This is one of those things I had a bunch when I was growing up. It was one of those easy throw on the table, no heat, good for hot days dishes. It's usually served as one of a number of dishes family style with rice.
The picture is... maybe not the most appetizing. And this might be a bit of an acquired taste. Century eggs are a bit pungent and rich and musky. I don't know how else to describe it. It's one of those you just have to try to understand things. I bought a box of 6 for $4 and they are a pantry item. As far as I know of, they don't go bad like ever. It doesn't cost much to try it and it's definitely authentic. You won't find this at any sort of takeout place. At least not around here.
The sauce is definitely an eyeball thing. Just don't go too heavy with the fish sauce or sesame oil. Probably could use more soy sauce but I'm not big on a lot of salt. Could also throw in anything you want, teriyaki sauce, oyster sauce, sweet chili sauce come to mind.
Century Eggs and Tofu
2 century eggs (preserved duck eggs)
1 block silken tofu
a small bunch finely chopped chives
1 tbsp soy sauce
1/2 tsp sesame oil
1 tsp rice wine vinegar
a couple drops fish sauce
Drain and chop up the silken tofu into chunks.
Peel the century eggs and cut into small pieces, about 1/4-1/8" cubes, and sprinkle on top of the tofu.
Sprinkle with chives
Drizzle all the sauces over.