French Onion Soup
French Onion Soup is easier than you think to make at home so you can cuddle up with a big bowl of hot, herby beef broth loaded with deeply flavorful caramelized onions and ooey gooey Gruyere croutons any night of the week!  In the post, I’ve included detailed instructions, tips for perfect caramelized onions, how to make French Onion Soup without oven safe bowls, how to make ahead and how to freeze!
Servings Prep Time
6servings 20minutes
Cook Time
Servings Prep Time
6servings 20minutes
Cook Time
up close of top view of Best French Onion Soup with a spoonful of cheesy bread
  • 6tablespoons unsalted butter
  • 2tablespoons olive oil
  • 4pounds yellow onions (about 6 medium onions) peeled, halved, sliced into 1/4” strips from top to bottom through the root end
  • 1/2teaspoon brown sugar
  • salt
  • pepper
  • 4-6 garlic clovesminced
  • 1/2cup water
  • 1tablespoon balsamic vinegar
  • 1tablespoon Worcestershire
  • 1tablespoon reduced sodium soy sauce
  • 2tablespoons flour
  • 8cups low sodium beef broth
  • 2 bay leaves
  • 1tablespoon fresh thyme leaves or 1 teaspoon dried
  • 1/2teaspoon dried parsley
  • 1/4tsp EACH dried oregano, paprika
  • 1-8-1/4teaspoon red pepper flakes
Cheesy Croutons
  • 6slices crusty artisan bread or 12 slices thinner baguette slicessliced into 1/2-inch thick slices
  • 6oz. shredded Gruyere cheeseabout 1 1/2 cups
  1. Melt butter with olive oil in a Dutch oven or heavy bottom stock pot. Add the onions, brown sugar, salt and pepper. Increase heat to medium high and cook for 5 minutes, stirring often.
  2. Reduce heat to medium and cook onions, stirring frequently (especially towards the end so they don’t burn), scraping the bottom and sides of the pan, until they are deeply browned, 40-50 minutes. Turn heat down if the onions scorch or stick to the pan (I turn heat down the last 15 minutes).
  3. Add garlic and cook for 30 seconds over medium heat. Add water, balsamic vinegar, soy sauce and Worcestershire sauce and stir to scrape up any browned bits on the bottom of the pan. Cook until liquid is absorbed.
  4. Sprinkle flour over onions and cook while stirring for 2 minutes.
  5. Add the beef broth, bay leaves, thyme, ¼ teaspoon salt, ¼ teaspoon pepper and all seasonings.
  6. Bring soup to a boil then reduce to a gentle simmer. Simmer uncovered on LOW for 20 minutes, stirring occasionally.
Cheesy Croutons
  1. When ready to eat, toast bread by spreading slices in an even layer on a baking sheet. Broil on the middle rack of the oven until golden, 5-7 minutes. Flip over and broil another 3 minutes or until golden. Sprinkle bread with Gruyere and broil on the middle rack until cheese melts, 3-5 minutes.
  2. Ladle soup into bowls and top with 1-2 cheesy crouton slices (depending on if you used a loaf or baguette).
  3. Alternative method for OVEN SAFE bowls: Ladle soup into bowls, top with a slice of bread then cheese. Place bowls in the oven on the middle rack and broil 3-5 minutes or until cheese is melted.
Recipe Notes

How to cut onions (see post for photos):

  1. Using a sharp chef’s knife, trim off both root and stem ends of the onion.
  2. Slice onion in half through the root and stem and peel off the skin.
  3. Thinly slice onions lengthwise, from the root to the stem, into ¼” wide slices. This helps them hold their shape during cooking, whereas, crosswise cut onions tend to fall apart when cooked.  Try and slice your onions roughly the same size so they cook evenly.

Tips for Caramelized Onions

  • Cut onions uniform: Try and slice your onions into uniform slices so they cook evenly.
  • Don’t slice onions too thin: Keep your onion slices about ¼” thick, erroring on the side of thicker.  They might seem thick but will cook down considerably.  Onions that are too thin will end up get stringy and mushy – we don’t want that!
  • Generous butter and olive oil: Don’t skimp on the butter!  Not only does it add flavor but it keeps the onions from sticking and scorching while cooking. The olive oil will keep the butter from burning a well as add flavor.
  • Cook over medium heat: Cook the onions over medium heat until deeply caramelized, reducing the heat if the onions start sticking to the pan or scorching. We want them to cook slow as the flavor comes from golden caramelization and not burning.
  • Stir: You don’t need to stir your onions constantly, but you do need to stir them every few minutes to ensure they are cooking evenly.  You will want to stir them more often when they are reduced and mostly caramelized because then they have a stronger chance of burning.
  • Caramelize more: when your onions look caramelized, go for more   My onions looked pretty caramelized at about 30 minutes, but I reduced the heat to low and continued to cook and stir for another 10 minutes and the results were breathtaking because the deeper the color, the deeper the flavor!

What Beef Broth is Best?

What Store bought Beef Broth is Best?

While homemade beef broth will win every time, there are some great store bought alternatives.  Cook’s Illustrated conducted a study on the best supermarket beef broths and testers ranked:

  1. Rachel Ray Stock-In-A-Box All Natural Beef Flavored Stock:  Tasters called it “steak-y” and “rich” with “thick body.”  It starts with beef stock and a shorter list of ingredients than the number 2 rank for a more fresh, real meat and a really beefy flavor.
  2. College Inn: relies more on beef derivatives which gives the stock flavor and body.

I also really like Kitchen Basics and Trader Joes Organic Beef Broth.   What’s your favorite brand?

Make Ahead French Onion Soup 

French Onion Soup tastes even better if made a day or 2 in advance, so I highly encourage you to make it ahead of time!

To make French Onion Soup ahead of time, follow the recipe as directed up to the point of completing the soup but not adding the cheesy croutons.  Add soup to oven proof bowls or an airtight container and store in the refrigerator for up to 4 days.

If storing soup in an airtight container:

Warm soup on the stove and proceed with recipe instructions.

If using oven safe bowls:

  1. When ready to serve, preheat the oven to 350 degrees.
  2. Transfer bowls straight from the refrigerator into the preheated oven.
  3. Reheat the French Onion Soup for 20 minutes then remove from the oven.
  4. Turn oven from bake to broil.  Toast bread as instructed per recipe instructions.
  5. Top soup with a slice of bread then grated cheese.
  6. Return to oven on the middle rack and broil 3-5 minutes or until cheese is melted.

How to Freeze Onion Soup 

You can freeze French Onion Soup without the cheesy croutons.  To freeze:

  1. Let soup cool completely.
  2. Add Soup to freezer safe containers or freezer size bags.
  3. Freeze for up to 3 months.
  4. When ready to eat, let soup defrost in the refrigerator overnight.
  5. Warm individual servings in the microwave or warm on the stove until heated through.