Allium appeal - Know your onions

A recipe for comforting French Onion Soup

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If there’s one single ingredient it would be a challenge to produce a well-flavoured dish without, it’s the onion. 

I can vouch for this first hand. In the Soviet years I lived in Moscow, the onion would disappear in October, to reappear as a new crop only in May. Sometimes in November random piles of onions turned up in the markets. But pick one up and it would subside in a reeking slump against the fingers, constrained only by its skin from oozing into your palm. Responsible dog walkers will know the sensation.

Not for nothing are they the third vital element in the mirepoix trinity of carrot and celery. They are key to the flavour foundation of every dish to which they are assigned. To test, look through your cookbooks and see how many recipes you can find in any cuisine (aside from those in Baking and Desserts) that don’t call for an onion or one or more of its close relations, the shallot, leek, garlic bulb, spring onion or chive.

Each of them is part of the Allium family, one of the oldest species of vegetable. Iran, Central Asian nations and India all claim to have been the first to cultivate it, over 7000 years ago. The Plymouth Brethren discovered they needn’t have shipped it to America - Native Americans were already growing it. Traces have even been found in Bronze Age settlements in China.

China produces 45% of global supplies. But while traditional Chinese medicine has it that the onion is good for relaxing the intestines and generally regulating the entire body and digestive system, Chinese cuisine more commonly uses scallions, green onions, than what they refer to as ‘Western onion’. 

At village fetes across Britain every summer, smallholders vie to win the red rosette for the largest onion. So far, the record goes to Tony Glover, whose entry to the Harrogate Autumn Flower Show in 2014 weighed 8.5kg, nearly 19 pounds. Perfect for a witches’ cauldron of onion soup.

And onion soup is the ideal soup for this chilly and dreich (that splendid Scottish word for ‘dull and gloomy’) time of year. 

Initially, it’s an olfactory challenge, the introduction of onions to heat infusing the entire house with the stench of unwashed bodies. Then the slow, low-temperature cooking in butter encourages the onion’s fructose or sugars to develop and mellow into a warm caramel-ly smell, full of comforting promise. 

It’s those sugars that, when broken down in the gut by its bacteria, cause - how shall I put it - the fart. (If Chaucer was happy with that expressive word, so am I.) The monks and Lamas of Tibet avoid anything onion because the flatulence - a beautifully onomatopoeic word - subsequently provoked disturbs meditation. 

There are more physical challenges, with exposure to its juices making your eyes sting. That culprit is Lachrymatory-factor synthase, an enzyme that was only discovered, would you believe, in 2002 in Japan. Previously it was believed a chemical irritant called syn-propanethial-S-oxide caused the lachrymal glands to release tears. (I offer you this information as a diversion from endless discussions of the causes of Covid-19.) 

The crying effect may be slightly mitigated by holding the onions under water as you peel them, and chopping them with your head held as far back as you can to evade their fumes but not so far you chop your fingers off. 

British food writer Nigel Slater has an onion soup recipe in his lovely bedtime read, The Kitchen Diaries, that avoids the agony by roasting the onions until collapsed, then chopping them and simmering them first in wine then in stock, to create the soup.

I prefer the Paris bistro method, made a day or two ahead and reheated so that the flavours become even more mellow. But read Meg Bortin’s recipe at the excellent The Everyday French Chef for a surprising revelation about that assumption!

Serves 4 - 6

5 tablespoons unsalted butter, 2 tablespoons of it cubed and chilled

1 tablespoon vegetable oil

1.5kg/3.3lbs onions, halved lengthwise, peeled, and thinly sliced

1 teaspoon salt

freshly ground black pepper

1 tablespoon sugar

350m/¾ pint dry white wine

1.5 litres/3 ¼ pints beef stock

10 sprigs fresh thyme, tied together

2 bay leaves

1 baguette

1 large garlic clove, unpeeled and cut in half crosswise

2 tablespoons Cognac or more

200g/7oz Gruyère, grated 

In a large pot, melt 3 tablespoons butter over medium heat. Lower the heat and add the oil and onions. Cover and saute the onions until soft, stirring occasionally, 15-20 minutes, then add the salt, pepper and sugar. Remove the lid, and continue to cook, stirring frequently, until the onions are caramelised to a deep golden brown. Read a book - it will take ages. If the onions begin to catch and brown too fast, turn off the heat or the soup will taste bitter. 

Add the wine and raise the heat to high, scraping up the onion caramel. Cook until almost all liquid has evaporated, stirring frequently. Add the stock and herbs to the pot. Bring to a boil, reduce to a simmer, then cook, uncovered, 20 to 30 minutes, until the soup has become a little syrupy.

Remove from the heat, adjust the seasoning if necessary, and whisk in the remaining cubes of butter. 

Heat the grill. Slice the baguette into two slices per person. Toast them until gold on each side. Rub one side of each toast vigorously with the garlic clove and set aside.

Set warmed heatproof bowls into a roasting pan, add half a tablespoon of brandy or more to the bottom of each, and ladle soup on top. Top each serving of soup with two garlic-rubbed toasts. Divide the cheese among the servings, covering the bread and soup surface. Slide the pan under the grill until the cheese is melted and bubbling. If you have eaters who don’t like soggy toast, top each garlic-rubbed toast with some cheese and grill them alone, for passing separately.