The sight of an omelet sizzling in a pan is a beautiful thing—until the diced onions you carefully folded inside turn blue. Wondering what tainted your meal? You’re not alone. Let’s break down the ...

Onions come in all different colors. There are red onions, perfect eaten raw on burgers or in salads, and white and yellow onions, which are excellent all-purpose choices. There are even green onions, ...