French Onion Soup
A deeply savory, soul-warming classic built on a foundation of slowly caramelized onions in a rich, herb-infused broth. Topped with a crusty bread slice and a blanket of melted, bubbly cheese, every spoonful is the perfect balance of sweet, savory, and indulgent.
For 4 servings
- prep
Prep the onions and garlic.
Peel and halve the onions, then slice thinly into half-moons. Mince the garlic cloves. Grate the cheese and set aside.
- saute · ~50 min
Caramelize the onions.
1.Melt butter with olive oil in a large heavy-bottomed pot over medium heat.2.Add the sliced onions and a pinch of salt. Stir to coat.3.Cook, stirring every 5-7 minutes, until deeply golden brown and jammy, about 45-50 minutes.4.Reduce heat slightly if onions start to scorch; a little fond on the pot bottom is good.TIPDon't rush this step. The deep color is where the flavor lives — aim for a rich mahogany brown. - saute · ~3 min
Build the soup base.
1.Add the minced garlic to the caramelized onions and cook until fragrant, about 1 minute.2.Sprinkle flour over the onions and stir constantly for 2 minutes to cook out the raw flour taste. - simmer · ~30 min
Deglaze and simmer the soup.
1.Pour in the white wine and scrape the bottom of the pot with a wooden spoon to lift all the browned bits.2.Let the wine bubble and reduce by half, about 3 minutes.3.Add water, bay leaves, and fresh thyme sprigs. Season with salt and black pepper.4.Bring to a boil, then reduce heat to low. Cover and simmer gently for 25-30 minutes. - bake · ~10 min
Toast the baguette slices.
1.While the soup simmers, preheat the oven to 400°F (200°C).2.Arrange baguette slices on a baking sheet and bake until dry and lightly golden, about 8-10 minutes.3.Remove and set aside. Leave the oven on. - assemble
Ladle and top the soup.
1.Remove bay leaves and thyme sprigs from the soup. Taste and adjust seasoning.2.Ladle the soup into 4 oven-safe soup bowls, filling each about three-quarters full.3.Float 2 toasted baguette slices on top of each bowl.4.Generously heap the grated Gruyère cheese over the bread, covering it completely and letting some fall onto the edges. - bake · ~5 min
Broil until bubbly and golden.
Place the bowls on a baking sheet and set under the broiler. Broil until the cheese is melted, bubbly, and deeply browned in spots, about 3-5 minutes. Watch carefully to avoid burning.
TIPPlace bowls on a baking sheet for easy transfer in and out of the oven — cheese drips are expected. - serve
Serve immediately.
Let the bowls cool for a minute or two, then serve piping hot. Warn diners that the bowls are extremely hot.
What to keep in mind.
6 tips from the recipe — small details that make a real difference to the final dish.
- 1Use a mix of yellow and red onions for a more complex sweetness.
- 2Deglaze the pot with wine or sherry to lift all the browned fond off the bottom.
- 3Toast the baguette slices until bone-dry so they stay crisp under the broiler.
- 4Grate your own Gruyère from a block — pre-shredded cheese won't melt as smoothly.
- 5Make the soup base up to 3 days ahead; the flavor deepens overnight in the fridge.
- 6Let the caramelized onions go past golden to a deep mahogany for the richest broth.
Adapt it for your goals.
Vegetarian
Swap water for a high-quality vegetable broth and use a vegetarian Gruyère alternative (or omit cheese) to keep the deep umami of caramelized onions without meat-based stock.
gluten freeGluten-free
Replace the all-purpose flour with a gluten-free all-purpose blend and use gluten-free bread (like a sturdy GF baguette) for those with gluten sensitivities.
low oilLow-oil
Reduce butter to 1 tbsp and use a non-stick pot; caramelize onions with a splash of water or broth to prevent sticking, cutting fat while maintaining deep flavor.
cheese lover'sCheese-lover's
Top the soup with a mix of Gruyère, Emmental, and a sprinkle of Parmesan for a nuttier, more decadent cheese crust.
Why this is on our healthy list.
Rich in Antioxidants
Onions are packed with quercetin, a potent antioxidant that helps reduce inflammation and supports heart health.
Good Source of Calcium
Gruyère cheese provides a healthy dose of calcium, essential for strong bones and teeth.
Low in Added Sugar
This savory soup relies entirely on the natural sweetness of caramelized onions, with no added sugars, making it friendly for balanced diets.
Contains Anti-Inflammatory Herbs
Fresh thyme and bay leaves contribute anti-inflammatory and antimicrobial properties, adding subtle wellness benefits to every bowl.
Frequently asked questions
Yes, Comté, Emmental, or even a good melting Swiss cheese work well, but avoid hard cheeses like cheddar as they can become greasy.
