Simple recipe, foggy origins

Onion soups in general have been around for a while, having originated in Ancient Rome. However French onion soup was codified in earnest in the 18th century. There are a few versions of how it came to be, but an enduring legend is that King Louis XV invented it one night. Rebecca Hays speaks on this in her book "Cook's Illustrated Revolutionary Recipes":

"[He] invented onion soup after returning home to an empty larder late one night [after] a hunting excursion. He took the few ingredients that he could find - a sack of onions, leftover beef stock, and a bottle of champagne - and created the now-famous recipe (pg 48)".

The first written recipe for French onion soup is credited to the head chef to a French prince, called then "peasant-style onion soup". There are also theories that it originated in Alsace, however it is popular across France, and no region claims it as their own.

In general, the onion was regarded as peasant food in these days, and royalty and upper classes tended to steer clear of it. This was their loss: these days it is understood that affordable "peasant food" is often the most delicious and nutritious food out there, with elevated food like foie gras and caviar being more divisive and costly (though caviar is delicious, we have yet to get on board the foie gras train). In fact, there exists a medieval recipe of an "elevated" onion soup, that includes ginger, saffron, and other rare and expensive spices. This sounds like overkill to us, not to mention overly expensive for flavours that don't really need much adjusting.

This original version of onion soup was free of cheese, but that changed in the mid 19th century. The open air market in Paris known as Les Halles had a few different restaurants who served French onion soup au gratin - meaning with a heft dollop of cheese put under a grill to melt and brown. This was popular to both the workers who needed something heavy to keep them going through the day, as well as the bourgeoisie who were battling hangovers, and not contributing much to society at all. Thus, a legendary bridge between classes of cuisine was born.

Caramelizing Onions

Onions are cheap, versatile, and when prepared correctly, absolutely delicious. There are so many ways one can prepare an onion to create filling, savory dishes, but today we are focusing on caramelization of onions.

Onions have a relatively high amount of sugar, which when cooked properly, can contribute to a natural sweetness. To quote Harold McGee:

"The sugar and sugar-chain content of onions [...] is largely responsible for their readiness to brown when fried, and contributes a caramel note to the cooked flavour" (pg. 311-2).

This caramel flavour is the root (pun fully intended) of French onion soup, and can be helped along through adding a teaspoon of sugar when the onions are caramelizing. But how do we caramelize, exactly? The trick is preparation, patience, and a little bit of courage.

First, you want to slice the onions as thinly as possible. This helps in two ways:

1. Thinly slicing increases the surface area of the onion, creating more opportunities for different parts of the onion to brown, and;
2. With more surface area, the water in the onion will cook out much faster, which will brown the onion faster, which will help you eat French onion soup *sooner*, which is *soup-er*.

I believe we can all agree that reason 2 is enough motivation to cut these onions thin. A sharp knife will make quick work of all the chopping you need to do.

Second, you want to sauté your onions low and slow. This can take a while, but it's worth it. The reason for going slow is to break down the onion's structure while cooking. If the pan is too hot, the outside of the onion may brown, but it's inner structures will remain undercooked: This will give a raw and unpleasant flavour to the soup (Raw onion can be a great flavour, but not in this context). The nice part about low temperature sautéing is that it is relatively stress free, so have a glass of wine, hang out in the kitchen with friends or turn on a podcast, and keep an eye on the onions, stirring occasionally.

Finally, when the structure breaks down, keep cooking the onions. When you don't think you can take them any farther without burning them, add your next ingredients: The farther you take your caramelization, the stronger and better the flavour of the final soup will be. It can be scary to cook something for this long and see it get so dark - feel the fear and do it anyway, you will not regret it!

How to make it

Caramelize

Heat olive oil and butter in a pot at low heat, then add your onions. Stir the onions often for one and a half to two hours until they are fully caramelized.

Simmer

Once everything is caramelized, add garlic, salt, pepper and flour, and cook this for about 2 minutes. This makes a sort of roux for the soup.

Once the garlic smells great, add the wine and Worcestershire sauce and cook the alcohol out.

Add broth, thyme, and bay leaves and let that simmer for 20 minutes.

Broil and Serve

Remove the herbs, and divide the soup into four crocks. Top these crocks with croutons and grated cheese and broil them until browned and melty.

Let the crocks cool for a bit, and enjoy!

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