Yesterday I bought this 1 lt (1 qt) steel casserole in a chinese shop, and after boiling one egg, it's decolored and got black spots, as shown:
It's stainless steel, it weights 430g, and I guess it's fake, but i was so cheap that I couldn't resist.
Bäcken is a french brand, but their products look much higher quality than mine.
What it's happing here? How can steel be bad? It's safe to use?
Edit
Cleaned with warm water + soap before first use, then used to cook hard boiled eggs in unsalted water.