Soupe à l’oignon is one of the most beloved French dishes, especially during the colder months. Its flavor comes from slowly caramelized onions and a deep, savory beef broth.
Traditionally served gratinéed with melted cheese on top of a toasted baguette, it’s the kind of soup that warms the soul and comforts the body.
Peel and thinly slice the onions.
In a large pot, melt butter over medium heat. Add onions and cook, stirring often, until caramelized and golden brown (30-40 minutes).
Add flour and stir well. Cook for 2 minutes to eliminate the raw taste.
Deglaze with white wine, scraping the bottom of the pan.
Add beef broth, bring to a simmer, and cook for 30 minutes. Season with salt and pepper.
Preheat the oven grill.
Toast baguette slices until crisp.
Ladle soup into heatproof bowls, top with toasted bread and grated cheese.
Place under grill until cheese melts and browns slightly. Serve hot.