Onion

Parts of Winter Onions

The onion bulb is a storage organ adapted for the survival of long periods of drought and/or cold.  It is formed by the transformed lower parts of the leaves:

1.  Scaly leaves are the outermost layer, known as peels / skins / husks.  They are completely dead and dry, resembling paper-thin membranes, variously coloured (e∙g∙ brown, purple, white).

2.  Skinny leaves are the transitional form between the young inner leaves and the superficial scaly leaves.  Many people do not recognise them as a separate category and count them among the internal leaves.  However, this confusion may cause problems with some delicate dishes.

3.  Meaty leaves are thick, juicy, swollen layers filling the entire interior.  Their middles are the fleshiest and most dominant structures - this is the bulkiest mass used in everyday cooking.  Their uppermost poles converge, forming the dry upper apex (or a navel-like circle if the summer leaves are trimmed;  Fig∙1, labelled A).

4.  Buds are the youngest leaves.  Their tips or longer stretches can sometimes be greenish to green.  This is the germination centre giving rise to all other leaves.  Each leaf is pushed from the middle towards the periphery as the onion grows.  Then peripheral leaves lose water, harden, and turn to the outer husky shell.

5.  The stem is a highly shortened stalk, sometimes called the root disk (which actually is its inferior surface).  All leaves grow upwards on its upper side, while roots germinate from its bottom in the opposite direction into the soil.  Mature bulbs temporarily shed off the roots during the deepest metabolic inactivity.  From the cookery point of view, the stem and the adjacent bottommost ends of the meaty leaves create a firm bottom or the basis (Fig∙1, labelled B), which is often cut off and thrown away.

Cooking with Dry Onions

Whole bulbs with skins  

Mechanically cleaned (dry roots, spotty peels, and loose parts removed) and washed onions can be boiled in soups.  Typical usage is in sauerkraut soups and meaty goulashes.  Some like to suck up the mushy interior through the apex, others squeeze the ball with a spoon, and the mushy pulp pops out.  You can also cut the skin with a knife, of course.  The emptied outer envelope is not typically eaten (challenging to chew and swallow, quite risky and not recommended).

Skins  

The husks can be used for colouring soups and sauces.  Once the brown colour is eluted (they only release some of their colourants), fish out the papery scales from the food.  Alternatively, you can use a fine powder from pulverised skins.

Skinny leaves  

They taste well but are rather toughish and chewy.  Those who like their firmness can eat them without problems (thorough manducation is strongly recommended).  They are perfectly usable in soups, dips and sauces undergoing mechanical pressing or blendering - one or two minutes in a mixer is enough to turn them into a smooth pap.  Due to their lesser quality, they are often discarded (or dried and crushed into condiment dust) together with the brown husks.

Meaty leaves  

The intermediate part of the fleshy leaves (Fig∙2, green line) is the most succulent and delicious portion of the onion bulb.  Ideal for all cooking modalities (raw foods, boiling, frying, baking, etc∙), either alone or in combination with virtually any other ingredients.

Mayo Stew is a striking example of a dish relying on high-quality meaty leaves and the strict avoidance of skinny leaves.  Half-crisp-ish onion dices are the dominant gourmet feature in this unusual delicacy capitalising on their palatable texture and unique flavour reaction with hot mayonnaise.

The basis  

It is possible to chop the onion basis together with the meaty leaves if you do not mind, or prefer, their chunky nature.  Otherwise, discard or process it together with the husks and skinny leaves (drying, pulverising, mashing...).