"Sweet&Sour Eggs ("Süß-Saure Eier") or "Mustard Eggs" ("Senfeier") is a typical East German dish.
I remember mentioning it to people from the West who just cringed because the name suggests something rather gross than tasty.
But it is delicious!
The description "sweet&sour" refers to the sauce with which the eggs are served.
It's a roux-based sauce containing vinegar and mustard for a sour note and sugar that adds the
sweetness to it."