I recently bought a certain "light cast iron" that looks like a wok. Cooking on induction, it seemed to give my pork broth a black tinge. Broth was fine, but there was certainly something from the pan.
The wok is supposedly preseasoned, so I don't know why this happens. Any workarounds? Should I rub the inside of the wok with cooking oil and bake it in the oven upside down for 30 minutes?