Those spongy lumps of uncertain origin in instant cup noodles? Turns out consumers in Japan love them just as much as the main attraction.Nissin Food Products Co. now sells one of its ingredients as “mystery meat,” a term popularised by customers of the cheap, quick meals. Each 200-gram (7-ounce) box – equivalent to 47 cup noodles’ worth of the chunks – retails for 650 yen (US$4). On the back are various suggested recipes for the rehydrated protein, including pasta bolognese, a hamburger, or stuffed peppers.After its invention by Nissin’s founder Momofuku Ando 66 years ago, instant noodles have taken over...