Very important! #THE USE OF PREVIOUSLY SLICED ONIONS IS THE COMMON CAUSE OF FOOD POISONINGS# Either you carefully pearl layer by layer the quantity to be used without wounding the leftover. If sliced as seen below, throw away the leftovers. Never use a previously sliced or wounded onion even if it is refrigerated. It is full of toxins coming from killed germs. NB: WHEN GERMS ARE KILLED, THEIR TOIXINS ARE RELEASED! #Those who eat roast fish, 'soya' ( roast/burnt meat) , salads..should beware of previously sliced onions in them#. Also, know that heat does not destroy all toxins from bacteria. Therefore, the safety of using previously sliced onions in cooking is not also guaranteed. A sliced onion will magnet and kill germs from its environment. This explains why those who buy and sell onions, more especially those who sleep in the same room where bags of onions are stored, hardly catch colds, flu and most contagious infections.This also explains why very sick people get more better when sliced onions are placed on the corners of their rooms and beds, and more especially when closer to their head positions. The surfaces of these sliced onions magnet and kill germs floating within the environment, thereby purifying it from harmful bacteria. This also explains why when an onion is sliced and kept for a few hours, the sliced surface gradually becomes darker. This is due to the accumulations of toxins from killed germs. May you be richly blessed with this knowledge. Dr Richard FRU - GENIWA.