Growing up, eggs stewed in soy sauce made great after school snacks for when I was hungry and just needed a small bite to hold me over until dinner.
Taiwanese Soy Sauce eggs are often added to take out street food boxes and served over rice, usually with some other protein like deep fried chicken cutlets. There's also another variation of this recipe called Tea Eggs which are a similar recipe but contain tea leaves and you can typically find those in the 7-Eleven stores all over Taiwan.
I like this recipe because it's simple. Besides the eggs, you'll only need 3 other ingredients which you may most likely have in your kitchen pantry already. If you don't happen to have rock sugar, you can also substitute with just plain white sugar.
Tip: Peeling hard boiled eggs can be a pain. Make it easier by putting the cooked eggs in a bath of cold water and a teaspoon or two of baking soda. Yes, baking soda! It will make your egg peeling go much smoother.