There’s something so incredibly humble about onion soup. It’s absolutely one of my favorites but unfortunately I only ever get to make it in the restaurant or for myself, as the missus thinks she’s allergic to onions. (She’s not, because I whiz them up into loads of dishes without her knowing!)
If you have the opportunity, get hold of as many different types of onion for this soup as you can. Sweat them gently, and you’ll be amazed at all the flavors going on.–Jamie Oliver
Put the butter, 2 glugs of olive oil, the sage, and garlic into a heavy-bottomed, non-stick pan. Stir everything round and add the onions, shallots, and leeks. Season with salt and pepper. Place a lid on the pan, leaving it slightly ajar, and cook slowly over medium-low heat for 50 minutes without coloring the vegetables too much. Remove the lid for the last 20 minutes; your onions will become soft and golden. Stir occasionally so that nothing catches on the bottom. Having the patience to cook the onions slowly, slowly, gives you an incredible sweetness and an awesome flavor, so don’t be tempted to speed this bit up.
When your onions and leeks are lovely and silky, add the stock. Bring to the boil, turn the heat down and simmer for 10 to 15 minutes. You can skim any fat off the surface if you like, but I prefer to leave it because it adds good flavor.
Preheat the oven or broiler to maximum. Toast your bread on both sides. Correct the seasoning of the soup. When it’s perfect, ladle it into individual heatproof serving bowls and place them on a baking sheet. Tear toasted bread over each bowl to fit it like a lid. Feel free to push and dunk the bread into the soup a bit. Sprinkle with some grated Cheddar and drizzle over a little Worcestershire sauce.
Dress your reserved sage leaves with some olive oil and place one on top of each slice of bread. Put the baking sheet into the preheated oven or under the broiler to melt the cheese until bubbling and golden. Keep an eye on it and make sure it doesn’t burn! When the cheese is bubbling, very carefully lift out the baking sheet and carry it to the table. Enjoy.
Here was a surprise. Much as Jamie Oliver says, the secret is in allowing the onions and others to sweat for a long time to bring the sweetness out. The end result was a delicious onion soup with a sweet yet peppery taste due to the sage. It’s very easy to prepare — and to enjoy on a cold night. I was afraid my daughters would not care for the strong sage taste, but quite the opposite: Everyone loved it. I used turkey broth, as opposed to chicken or beef, as I had some homemade I needed to use.