Onions are among the world’s oldest cultivated plants. They were probably known in India, China, and the Middle East before recorded history. They seem to have been cultivated in excess of 7,000 years.
Onions are versatile and an essential ingredient in Indian cuisine. Native to Asia, these underground bulbs are prized all over the world for the depth and flavour that they add to savoury dishes. Dry onions are fully matured, with juicy flesh and dry, papery skin and have a pungent flavour that becomes quite sweet upon lengthy cooking.
Note that some Indians will not eat onion (or garlic) for religious reasons.
The onion’s characteristic pungency results from the sulfur-rich volatile oil it contains; the release of this oil during peeling or chopping brings tears to the eyes.
They are used for their flavour, if cooked quickly, or for their thickening properties if cooked slowly.
Varieties of onion differ in size, strength and colour.
The yellow or brown onion has pale golden skin, greenish-white flesh and a strong taste. It is the most used type of onion in this book.
Red onions are an attractive, milder alternative to the brown onion with a shiny purple skin and the edge of each of its white rings tinged with red. They are often called Spanish onions. It is frequently used in the recipes in this book, particularly in South Indian dishes.
Shallots are a sub-species of onion; they are small and boast a delicate flavour. We tend to use them for fish or seafood based dishes.
Green onions are immature onions pulled before the bulb is fully formed, and can be recognised by their long green leaves. Like red onions, they are fairly mild and often used raw in salads. Green onions are also known as spring onions or scallions. The green hollow tops make a great garnish when finely sliced.
Choose onions that are firm, or even hard, with tightly closed necks that are absolutely dry, avoiding those with a thick, woody center in the neck. The skin should be bright and shiny. If you notice dark, powdery patches under the skin, reject it, as this is an indication of a mould which will eventually spoil the flesh.