There’s nothing quite like the fragrant steam rising from a bubbling pot of French Onion Soup on a chilly evening. I’ve stirred these caramelized onions dozens of times, listening to their gentle sizzling and watching the broth turn a deep amber. Through multiple tests, I discovered that a mandoline-sliced onion yields the most consistent golden edges and a silkier broth.
Why You’ll Love French Onion Soup
- Deeply savory broth enriched by slow-cooked onions
- Silky texture with tender onion ribbons
- Golden, bubbling cheese layer that crackles as it cools
- Simple pantry ingredients come together beautifully
- A taste of French culinary tradition in every spoonful
A Little Background
My first winter test of this French Onion Soup was in a drafty kitchen, turning a simple pot of onions into a fragrant treat that drew friends over for warmth. I learned early on that uniform slices—thanks to my trusty mandoline—gave me smoother caramelization, elevating each spoonful.
Key Ingredients for French Onion Soup
- Onions (8 large): Halved and thinly sliced for even browning; mix yellow and sweet varieties for depth.
- Butter or Ghee (3 tbsp): Coats onions for a rich mouthfeel; ghee adds a hint of nuttiness.
- Garlic & Fresh Thyme: A quick 1-minute sauté brings out their aromatic lift.
- Dry White Wine (¼ cup): Deglazes the pan and adds subtle acidity; omit or swap for sherry.
- Gruyère Cheese (1½ cups): Melts into a glossy, golden crust; Swiss or Comté can be used.
How to Make French Onion Soup
- In a heavy pot, melt 3 tbsp butter and 2 tbsp olive oil over medium heat. Add 8 halved, thinly sliced onions and stir to coat. Cook, stirring every few minutes, until onions are very soft and golden brown, about 45 minutes.
- Add 2 minced garlic cloves and 1½ tsp fresh thyme leaves; sauté until fragrant, about 1 minute. Pour in ¼ cup dry white wine, scraping up browned bits; let it evaporate, about 1–2 minutes. Stir in 6 cups low-sodium broth and 1 bay leaf; bring to a gentle simmer and cook 10 minutes. Mix in 2 tsp Worcestershire sauce, season with salt and pepper.
- Preheat the oven to 400°F. Ladle the soup into oven-safe bowls. Arrange toasted baguette slices on top and sprinkle with 1½ cups grated Gruyère.
- Bake until the cheese is melted, bubbling around the edges, and lightly browned, about 5–10 minutes. Serve immediately while still crackling.
Pro Tips & Troubleshooting
- Stir every 5 minutes for even caramelization; I found less stirring led to uneven browning in my second trial.
- If onions begin to stick, lower heat slightly and add a splash of water to loosen fond.
- For a seasonal twist, swap white wine for apple cider or sherry for a touch of autumnal sweetness.
- Doubling the recipe? Use a wider pot to maintain a single layer of onions for uniform cooking.
Storage & Make-Ahead Guide
Let soup cool slightly but don’t leave it at room temperature more than 2 hours. Store in airtight containers in the fridge for up to 4 days or freeze up to 3 months. I tested freezing in individual mason jars—thawed overnight in the fridge, the texture stayed remarkably smooth. Reheat over medium heat until steaming, then add fresh baguette and cheese.
Serving Suggestions
Pair with a crisp mixed greens salad or drizzle a little truffle oil on the cheese crust for an elegant touch. Swap baguette rounds for garlic croutons or serve with a side of melted raclette for extra cheesiness.
Frequently Asked Questions
- What onions are best for French onion soup? Yellow onions are classic for their balance of sweet and savory; mixing in sweet onions adds depth.
- Can I make French onion soup vegetarian? Yes—use vegetable broth and swap Worcestershire sauce for a vegan version or soy sauce.
- How do I store leftover French onion soup? Cool within 2 hours, refrigerate up to 4 days or freeze for 3 months, then reheat gently.
- Can I use Parmesan instead of Gruyère? Parmesan melts less fluidly but adds a sharp bite; combine with mozzarella for stretch.
- Can I prepare French onion soup ahead of time? The soup base can be made a day ahead; add bread and cheese just before baking.
- How do I ensure onions caramelize without burning? Maintain medium heat, stir regularly, and adjust with small splashes of water if needed.
Final Thoughts
After countless batches, my favorite ritual is tucking into this French Onion Soup by candlelight, savoring each silky spoonful topped with bubbling cheese. I’d love to hear how yours turns out—share your photos and tweaks below!
More Recipes You’ll Love
- Butternut Squash Soup Recipe – a creamy, seasonal counterpart to French Onion Soup
- Simple Potato Soup – hearty, rustic flavors that pair beautifully with crusty bread
- Slow Cooker Chicken Noodle Soup – comforting slow-cooked broth technique
- French Onion Beef Short Rib Soup – a meaty twist on classic French Onion Soup
French Onion Soup
Ingredients
Soup Base
- 8 large onions halved and thinly sliced
- 3 tablespoons unsalted butter
- 2 tablespoons olive oil
- 2 cloves garlic minced
- 1.5 teaspoons fresh thyme leaves
- 0.25 cup dry white wine
- 6 cups low-sodium chicken broth
- 1 bay leaf
- 2 teaspoons Worcestershire sauce
- Salt and pepper to taste
To Serve
- Sliced baguette toasted
- 1.5 cups grated Gruyère cheese
Instructions
Soup Base
- Melt butter and olive oil in a heavy pot over medium heat.
- Add onions and stir to coat; cook, stirring every few minutes, until golden brown, about 45 minutes.
- Stir in garlic and thyme; cook until fragrant, about 1 minute.
- Pour in white wine, scraping up any browned bits; simmer until mostly evaporated, 1–2 minutes.
- Add broth and bay leaf; bring to a gentle simmer and cook 10 minutes. Stir in Worcestershire sauce and season with salt and pepper.
To Serve
- Preheat oven to 400°F. Divide soup among oven-safe bowls, top with toasted baguette and Gruyère.
- Bake until cheese is melted and bubbling, about 5–10 minutes. Serve immediately.