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This single serving French Onion Soup is rich, bold, and perfectly portioned. Caramelized onions simmer in a savory broth, then it’s topped with toasted French bread and melted cheese for a classic, comforting finish.

A bowl of french onion soup on a metal tray with a glass and bottle of red wine and a spoon.

Why You’ll Love This Recipe

  • Simple Ingredients: Made with one onion and basic pantry staples.
  • Rich and Comforting: Savory broth, caramelized onions, and melted cheese in every bite.
  • Bistro Flavor at Home: Classic French Onion Soup without the restaurant price.
  • Easily Doubles: Double the ingredients for two satisfying servings.

What I love most about this French Onion Soup is how it transforms basic ingredients into something so rich and satisfying. Slowly caramelized onions simmer in a flavorful broth, and the whole bowl is topped with crusty bread and bubbling, melted cheese.

It’s the kind of meal that feels comforting and a little indulgent, without being complicated or time-consuming. When I want something warm and flavorful that feels like a treat, this is the recipe I turn to.

Pair your French Onion Soup with a crisp Brussels Sprouts Salad, Baked Chicken Thighs, or Crustless Quiche Lorraine. For dessert, add a slice of Lemon Cake. Want more soups? Browse our full collection of single serving soup recipes?

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Ingredients

If you have any ingredients leftover from this small batch French Onion Soup recipe, check out our Leftover Ingredients Recipe Finder

  • Butter: Adds richness and is used to sauté the onions.
  • Onion: Use a small yellow onion, thinly sliced for even caramelization and natural sweetness.
  • Garlic: One clove adds subtle depth without overpowering the soup.
  • Seasonings: A mix of dried thyme, salt, and black pepper balances and enhances the flavor.
  • Red Wine: Deglazes the pan and adds depth. You can substitute with chicken or beef broth if preferred. Leftover wine? Use it in Coq au Vin, Beef Stew, or Sangria.
  • Flour: Slightly thickens the soup. Use a gluten-free flour blend if needed.
  • Broth: I prefer chicken broth for a cleaner flavor. Beef broth is traditional but can taste metallic if store-bought.
  • French Bread and Cheese: A slice of crusty bread topped with melted Gruyere completes the soup. Gouda, Swiss, Fontina, or Mozzarella are great alternatives.

Recipe Variations

Here are some delicious ways to customize your French Onion Soup:

  • Vegetarian Version: Use vegetable broth instead of beef or chicken broth. Add a splash of soy sauce or vegetarian Worcestershire sauce for a richer flavor.
  • Wine-Free Option: Skip the red wine and deglaze the pan with broth for a flavorful, alcohol-free alternative.
  • Heartier Soup: Add thin slices of cooked beef or shredded chicken to turn your soup into a filling, complete meal.

How To Make French Onion Soup

These photos and instructions are here to help you visualize how to make a single serving of French onion soup. See the recipe box below for ingredient amounts and full recipe instructions.

  1. Caramelize the Onions
    • Melt the butter in a 2-quart saucepan over medium heat.
    • Add the sliced onions, garlic, thyme, salt, and pepper. Cook for about 25 minutes, stirring occasionally, until the onions are very soft and caramelized.

Tip: Take your time with the onions—caramelizing slowly over medium heat brings out their natural sweetness and builds the rich flavor this soup is known for.

onions caramelizing in a pot.
  1. Deglaze with Wine
    • Pour in the wine and bring it to a boil.
    • Reduce the heat to a simmer and cook until the wine evaporates, about 5 minutes.
red wine deglazing a pan.
  1. Thicken the Soup
    • Sprinkle the flour over the onions and stir to combine.
    • Lower the heat to medium-low and cook for 10 minutes, stirring occasionally to prevent the flour from burning.
red wine mixed with onions and flour in a pot.
  1. Simmer with Broth
    • Stir in the chicken broth and bring the soup back to a gentle simmer.
    • Let it cook for 10 minutes, stirring occasionally.
french onion soup simmering in a pot.

Prepping The Bread

While the soup simmers, get your bread ready to top off the dish.

  1. Broil the Bread
    • Heat the broiler. Place the slice of French bread on a baking sheet.
    • Sprinkle Gruyere cheese generously over the bread.
    • Broil for 3-4 minutes, or until the cheese is bubbly and golden brown.
a wedge of french bread topped with melted cheese on a baking sheet.
  1. Serve
    • Place the cheesy bread in a soup bowl and pour the hot soup over it. Enjoy immediately.
A spoonful of french onion soup from a bowl on a metal tray with a glass and bottle of red wine.

Expert Tips

  • Slice Onions Thinly: Thin, even slices caramelize more evenly and ensure every spoonful of soup has tender, flavorful onions.
  • Low and Slow Cooking: Patience is key when caramelizing onions. Cooking them over low to medium heat allows their natural sweetness to develop fully without burning.
  • Gruyere Cheese: Gruyere melts beautifully and delivers the classic nutty flavor that defines French Onion Soup. If unavailable, try Gouda, Fontina, or Mozzarella.
  • Selecting the Best Broth: Beef broth is traditional, but store-bought varieties often have a metallic taste that can overpower the soup. Chicken broth provides a more balanced, mild flavor and works wonderfully in this recipe. If you’re aiming for a vegetarian version, high-quality vegetable broth is another excellent option.

Frequently Asked Questions

Which type of onion is best for French onion soup?

Yellow onions are the best choice for their natural sweetness, but you can use white onions or even red onions if needed.

Do I have to use wine in this recipe?

You can substitute the wine with additional broth. Wine adds depth and richness, but the soup will still taste great without it.

How do I store leftover French onion soup?

Store any leftover soup in an airtight container in the fridge for up to 3 days. Reheat gently on the stove over low heat.

RELATED: Single Serving Comfort Food Recipes

Ways To Use Leftover Ingredients

If you have any ingredients leftover from this recipe, check out our Leftover Ingredients Recipe Finder or you might like to consider using them in any of these single serving and small batch recipes:

If you’ve tried this single serve French onion soup recipe or any recipe on One Dish Kitchen please let me know how you liked it by rating the recipe and telling me about it in the comment section below.

If you take a picture please tag us on Instagram (@onedishkitchen) we’d love to see it!


Cooking For One Made Easy
Because you’re worth it

French Onion Soup For One

4.93 from 28 votes
By: Joanie Zisk
Prep: 10 minutes
Cook: 50 minutes
Total: 1 hour
Servings: 1 serving
This single serving French Onion Soup features sweet caramelized onions in a savory broth, topped with crusty bread and melted Gruyere cheese. Rich, classic flavor without the leftovers.

Watch How To Make This

Equipment

Ingredients 
 

  • 3 tablespoons salted butter
  • 1 small yellow onion -halved, then thinly sliced
  • 1 clove garlic -chopped
  • ½ teaspoon dried thyme
  • ¼ teaspoon kosher salt
  • teaspoon coarsely ground black pepper
  • ¼ cup red wine
  • 1 tablespoon all-purpose flour
  • 2 cups low sodium chicken broth
  • 1 thick slice French bread
  • ¼ cup shredded Gruyere cheese
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Instructions 

  • Caramelize the Onions: Melt the butter in a 2-quart saucepan over medium heat. Add the sliced onions, garlic, thyme, salt, and pepper. Cook, stirring occasionally, until the onions are very soft and caramelized, about 25 minutes.
  • Deglaze with Wine: Pour in the wine and bring to a boil. Reduce the heat to low and simmer until the wine has evaporated, about 5 minutes.
  • Add Flour for Thickening: Sprinkle the flour over the onions and stir to coat evenly. Lower the heat to medium-low and cook for 10 minutes, stirring occasionally to prevent the flour from burning.
  • Simmer the Soup: Stir in the broth and bring the soup back to a gentle simmer. Cook for 10 minutes, stirring occasionally. Taste and add more salt if needed.
  • Prepare the Cheese Bread: While the soup simmers, heat the broiler. Place the French bread slice on a baking sheet, sprinkle Gruyere cheese on top, and broil until the cheese is bubbly and golden brown, about 3-4 minutes.
  • Assemble and Serve: Place the toasted cheese bread in a soup bowl. Pour the hot soup over the bread and enjoy immediately.

Notes

  • Slice Onions Thinly: Thin, even slices caramelize more evenly and ensure every spoonful of soup has tender, flavorful onions.
  • Low and Slow Cooking: Patience is key when caramelizing onions. Cooking them over low to medium heat allows their natural sweetness to develop fully without burning.
  • Gruyere Cheese: Gruyere melts beautifully and delivers the classic nutty flavor that defines French Onion Soup. If unavailable, try Gouda, Fontina, or Mozzarella.
  • Selecting the Best Broth: Beef broth is traditional, but store-bought varieties often have a metallic taste that can overpower the soup. Chicken broth provides a more balanced, mild flavor and works wonderfully in this recipe. If you’re aiming for a vegetarian version, high-quality vegetable broth is another excellent option.

Nutrition

Serving: 1serving, Calories: 628kcal, Carbohydrates: 21g, Protein: 21g, Fat: 47g, Saturated Fat: 28g, Cholesterol: 126mg, Sodium: 1145mg, Potassium: 584mg, Fiber: 1g, Sugar: 4g, Vitamin A: 1365IU, Vitamin C: 6.1mg, Calcium: 379mg, Iron: 2.2mg

The information shown is an estimate provided by an online nutrition calculator. It should not be considered a substitute for a professional nutritionist’s advice.

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Iโ€™m Joanie, chef, author of The Ultimate Cooking for One Cookbook, and creator of One Dish Kitchen. With 10+ years of experience developing single serving and small batch recipes, Iโ€™m passionate about making cooking for one simple and enjoyable. So glad youโ€™re here!

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4.93 from 28 votes (10 ratings without comment)

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50 Comments

  1. Vanessa says:

    This is delicious! I used red wine and beef broth. Loved the Gruyere toasts on top! This made plenty for two big bowls!

  2. Lynn Kelly says:

    Getting ready to make this right now! French onion soup is one of my very favorites…next to Potato Leek! Thanks for sharing!

  3. Jubilet says:

    Made this today for lunch– tasted great and was exactly what I was craving. The recipe was easy to follow and the result was so good I almost wish I had leftovers!

  4. J. Hegyi says:

    Terrific recipe.

  5. Linds says:

    This was decadent and delicious. Thanks for the recipe! I made a few tweaks: deglazed pan with an aged balsamic vinegar, substituted Italian seasoning for the thyme (because I didnโ€™t have any thyme on hand), and used shredded mozzarella cheese for the bread.

  6. Christina says:

    This tasted amazing!