French Onion Soup

French Onion Soup is one of my favorite comfort foods, but I usually reserve this warm and cozy soup for restaurants because it takes time and patience to make. But I’ve come to realize that although it is a slow process, French Onion Soup is still ridiculously simple and inexpensive, so it’s totally worth the effort. It’s full of sweet caramelized onions, a rich and savory broth, crusty bread, and gooey cheese. You’ve got to make this incredible French Onion Soup recipe on your next day off while you’re relaxing with a movie or folding some laundry. I think you’ll be glad you did!

What is French Onion Soup?

If you’ve never had the pleasure, French Onion Soup is made with sweet caramelized onions, beef broth, and herbs, then topped with a piece of toasted bread and a generous heap of cheese, which are then broiled to perfection. With every spoonful, you get a piece of bread soaked with flavorful broth, melty cheese, and sweet-savory onions. It’s pretty epic.

What Else Can I Add to French Onion Soup?

I made this French Onion Soup recipe as simple as possible while still retaining its rich flavor. But if you want to go above and beyond, here are some other ingredients you can add:

Wine – Try deglazing the pot (after adding the flour) with about 1/2 cup of wine before adding the beef broth. You can use either a dry white wine or a red wine, depending on whether you want your soup to have a lighter touch (white wine) or a richer flavor (red wine).

Sweet Onions – I made my soup with your average everyday yellow onions, but if you want a tad more sweetness you can choose a sweet onion instead.

Brandy or Sherry – A couple of tablespoons of brandy or sherry added to your French Onion Soup at the end can brighten the flavors.

Garlic – I didn’t want to muddy the sweet delicate flavor of the onions, but a lot of people do prefer to also add garlic. If adding garlic, mince it up well and sauté it with the caramelized onions for a minute or two just before adding the flour.

How to Store Leftovers

Leftover French Onion Soup will stay good in the refrigerator for 4-5 days, or it can be frozen for about three months. Store the soup without the bread and cheese, and add them only after reheating. The soup can be reheated in the microwave or in a saucepot on the stove over medium-low heat, stirring often.

Love caramelized onions? Try our French Onion Dip recipe!

Love cozy soups? Check out all of our Budget-Friendly Soup Recipes!

How to Make French Onion Soup – Step by Step Photos

Begin by slicing 3 lbs. yellow onions into thin slices (about ¼-inch thick). Add the sliced onions to a large soup pot with 2 Tbsp olive oil. Cook the onions over medium heat, stirring occasionally.

When the onions begin to get a little golden color (after about 30-45 minutes) add 2 Tbsp butter. Continue to cook over medium heat, stirring occasionally.

The goal is to keep cooking until the onions become deep brown in color and have a jammy texture. If the bottom of the pot begins to brown faster than the onions, just add a couple tablespoons of water to dissolve the browned bits off the bottom and continue to cook. Do not stop when the onions are the color in the photo above. There is still a ways to go!

When the onions are the color of an old penny (see photo above), add 3 Tbsp flour and continue to cook and stir for about two minutes. The flour helps thicken the soup very slightly, just giving it a little extra body.

Finally, add six cups of beef broth to the pot. Stir to dissolve any browned bits off the bottom.

Also add ½ tsp dried thyme, one bay leaf, ¼ tsp freshly cracked pepper, and 1 Tbsp Worcestershire sauce. Bring the soup up to a simmer and let it continue to simmer for about 30 minutes. If you’re using a lower sodium broth, you’ll want to taste the soup and add salt to taste after it simmers.

Toward the end of the simmer time, begin to prepare the cheese toast. Preheat the oven’s broiler. Place slices of French bread on a baking sheet (I only had four soup bowls, so I’m only toasting four pieces right now, but the soup makes about 5 servings). Broil the bread for a few minutes on each side or just until it’s lightly golden brown. It will broil more later with the cheese.

If you have oven-safe bowls, portion the French Onion Soup into the bowls. If you do not have oven-safe bowls, pile the shredded cheese right onto the toasted bread on the baking sheet, then broil for a few minutes more to melt the cheese. Top each bowl of soup with a cheesy bread slice.

If you do have oven-safe bowls, place the bowls on the baking sheet and add a piece of toasted bread to each bowl, then top with shredded Swiss cheese or Gruyere.

Return the baking sheet with the bowls of soup to the oven and broil for a few minutes more, or until the cheese is melted and the bread is toasty. Every broiler is a little different, and they cook quickly, so keep an eye on them!

Dig in!