Without doubt the onion is the most used flavoring vegetable in the world. There is hardly a savoury dish that doesn't include onions or one of its relatives - white and red onions, garlic, chives, shallots, spring onions and leeks. Members of the onion family vary enormously in shape, size, colour, texture and intensity of flavor. Onions, particularly garlic, have also been used as medicines. The ancient Egyptians worshipped onions and during the Middle Ages they were used as currency. Onions give you some vitamin C and fiber. Scientists have recently discovered that flavenoids found in onions may protect people from heart disease. Cocktail onions These tiny onions have a sweet white flesh and are sold pickled in vinegar. They are the smallest variety available. Uses: Serve pickled cocktail onions with a selection of cold meats or with crusty bread and mature Cheddar cheese. To store: Keep in a cool, dark place for up to 1 year. Pearl onions Also known as button or baby onions, these are larger than pickling onions and have a sweet, delicate flavour. Uses: Add whole to stews and casseroles or cook them very gently in a little butter and a splash of balsamic vinegar for 20-30 minutes until tender, serve with roasted meat. Pickling onions These are maincrop onions, picked when they are still small. Available only in the autumn, they have a strong, pungent flavour. Seasonal availability: September to November. Uses: Preserve them in vinegar, leave to mature and enjoy them with cheese and cold meats. They can also be added whole to casseroles in place of shallots or standard onions. To store: Store in a dark, cool, airy place. To prepare: Chop off the neck and just a little of the base to help the onion stay together. Score a line down the side of the onion and peel away the outer skin and first layer of flesh. To make peeling easier, soak the onions in warm water to soften the skins. Red onions Red onions have a mild sweet flavour and an attractive colour. Uses: As a garnish or combine with tomatoes and red leaf lettuce for a colourful salad, or include in homemade chutneys to serve with cheese and cold meats. Try them quartered and roasted in olive oil. Seasonal availability: All year, English from October to April. To store: Store in a dark, cool, airy place. To prepare: Cut the neck and base away, then score down the side of the onion and remove the skin and first layer of flesh. To help hold back the tears during preparation, chill the onion first for 30 minutes and always remove the root end last. The root contains the largest concentration of sulphuric compounds which make the eyes water. Shallots These are not baby onions (as pickling onions are) but a close relation of the onion. They have a mild, delicate flavour which is less overpowering than most onions so do try to use shallots where a recipe specifies if possible. Shallots grow in a similar way to garlic - when you peel one there may be two or three held together at the root. Seasonal availability: All year. Uses: Use in recipes where a small amount of onion is used or where a subtle onion flavour is needed. They are often included in rich, creamy sauces where just a hint of onion flavour is needed. To store: Keep in a cool, dry place. To prepare: Top and tail shallots and then peel the outer skin away. If there are several bulbs, pull them apart and then slice. Spanish onions Onions grown in warm climates are milder than those from cooler regions, consequently Spanish onions have a mild, sweet flavour. Their skins are a rich golden colour and they are one of the largest varieties available. Seasonal availability: All year. Uses: Serve raw in salads, stuff and bake them or add to any savoury dish where a subtle onion flavour is required. To store: Store in a dark, cool, airy place. To prepare: Cut the neck and base away, then score down the side of the onion and remove the skin and first layer of flesh. To help hold back the tears during preparation, chill them first for 30 minutes and always remove the root end last. The root contains the largest concentration of sulphuric compounds which make the eyes water. Spring onions Also known as salad onions, these are onions that have been harvested at a very young age. They have green shoots and a creamy white bulb, both of which can be eaten. They have a mild flavour and are often eaten raw. Seasonal availability: May to September. Uses: In salads, stir-fries, omelettes or sandwich fillings. To store: Keep in the fridge for 3-4 days. To prepare: Trim off the root and the outer leaves. Serve whole or sliced, the green tops can be snipped using kitchen scissors. White onions With a strong, pungent flavour and distinctive white skin and flesh, white onions are increasingly popular. Uses: Ideal for serving raw in salads or cooked they are very versatile. Yellow onions These are the most commonly used onions and they have a golden brown skin. They have a pungent aroma, a strong flavour and are a good all-round onion. Seasonal availability: All year. Uses: In a wide variety of dishes from casseroles, pies and quiches to stir-fries, sauces and pizzas. To store: Keep in a dark, airy place. To prepare: Cut the neck and base away, then score down the side of the onion and remove the skin and first layer of flesh. To help hold back the tears during preparation, chill them first for 30 minutes and always remove the root end last. The root contains the largest concentration of sulphuric compounds which make the eyes water. Caramelization (British English: caramelisation) is the oxidation of sugar, a process used extensively in cooking for the resulting nutty flavor and brown color. As the process occurs, volatile chemicals are released, producing the characteristic caramel flavor. Like the Maillard reaction, caramelization is a type of non-enzymatic browning. However, unlike the Maillard reaction, caramelization is pyrolysis, as opposed to reaction with amino acids. When caramelization involves the disaccharide sucrose, it is broken down into the monosaccharides fructose and glucose.