Slow onion soup
This recipe is part of Ugly Vegetable Winter – weird winter vegetables that are delicious, locally grown, and often ignored.
Think about this dish as a way to explore the power of the humble onion. There are many shortcuts to make French onion soup: butter adds sugar to caramelize the onions faster, some recipes use baking soda to break down the cell walls, and beef stock is added for richness. Here the onions do all the work if you’re able to give them a lot of time to cook and become complex.
Ingredients
A side dish for 4 or a meal for 2.
Scales up easily! Caramelize as many onions as you can cut, you will never be sorry to have them in the freezer.
CARAMELIZED ONIONS
1kg onions, a mixed variety is ideal but any kind will work
4 tbsp olive oil
SOUP
1L water
1 bay leaf
1 tbsp thyme
Salt and pepper
INGREDIENT NOTES
You can speed up onions by using butter, adding sugar, or balsamic vinegar. These all create a caramelized coating that’s brown and sweet. Adding 1/8 tsp baking soda helps onions break down faster.
For this soup the onions cook for 4 hours at a low temperature until they are extremely deep and rich in flavour. You can stop at 45 minutes. I like the slow, all-day nature of the recipe – but it’s a luxury to be able to hang out in the kitchen for the day. Take the shortcuts where you need them, but slow down if you can.
Method
CARAMELIZE THE ONIONS
Cut the onions in half, remove the peel, then cut into thin strips. You will have an impossibly large amount of onions.
In a very large pot add the olive oil, onions, a big pinch of salt, and 1/4 cup of water. Set on medium-high heat, cover, and steam-cook for 10 minutes. The onions will rapidly soften and begin to release their water.
Remove the lid, reduce the heat to low (on my cooktop I use setting 3 of 10) and cook, stirring occasionally, until deeply caramelized. You will have an impossibly small amount of onions.
Due to the lack of butter the onions will take a long time to brown, but it also means they are less likely to burn. You can stop at around 45 minutes, but I usually let this go for 3–4 hours. The slow cook time creates a deep, rich flavour comparable to French onion soup made with beef stock.
MAKE THE SOUP
Add water, bay, thyme, salt, and pepper. Bring to a boil, reduce to a simmer, and simmer for 30 minutes. Remove the bay leaf.
SERVE
This soup is delicious on its own as a side dish.
To make it into a meal, serve it like French onion soup with garlic bread croutons (see Pumpkin Soup recipe on my website) and Emmental or Gruyère cheese.
For a vegan alternative, serve over top of olive oil fried bread, which creates a delicious crispy-gone-soggy flavour. Porridge bread is my favourite to use here.