Classic French Onion Soup

Classic French Onion Soup

From The Couple’s Cookbook: Recipes for Newlyweds

There’s something undeniably romantic about French onion soup. It’s slow, comforting, and deeply satisfying — the kind of dish that rewards patience and fills the kitchen with the most incredible aroma. Perfect for cozy nights in, this recipe from The Couple’s Cookbook is designed for two, making it ideal for a quiet dinner shared over candlelight.

What makes this version extra special is the addition of black garlic. Gently fermented, black garlic adds a subtle sweetness and complexity that beautifully complements the deeply caramelized onions — the true star of the show.

Serves

2

Prep Time

20 minutes

Cook Time

1 hour, 40 minutes

Ingredients

Soup

• 2 tablespoons salted butter

• 1 tablespoon olive oil

• 5 small yellow onions, thinly sliced

• ½ teaspoon kosher salt

• ¼ teaspoon freshly ground black pepper

• 1 small garlic clove, minced

• 2 black garlic cloves, minced

• ½ teaspoon chopped thyme

• 4 cups low-sodium beef stock

• ¼ cup dry red wine

• 2 teaspoons balsamic vinegar

• 3 ounces mozzarella, grated

• 3 ounces Gruyère, grated

Crostini

• 2 tablespoons extra-virgin olive oil

• 2 (1-inch-thick) slices sourdough bread

• Pinch of kosher salt

• Pinch of freshly ground black pepper

Instructions

Make the Soup

In a Dutch oven or heavy-bottomed skillet set over medium-low heat, melt the butter with the olive oil. Add the onions, sprinkle with salt, and cook for about 15 minutes, stirring occasionally, until softened and translucent.

Add the pepper, garlic, black garlic, and thyme. Continue cooking over medium-low heat for 20–30 minutes, stirring often, until the onions are deeply caramelized, mahogany brown, and sweet-smelling.

Pour in the beef stock, red wine, and balsamic vinegar. Bring to a boil, then reduce heat to low, cover, and simmer for 30 minutes.

Make-ahead tip: The soup can be cooled slightly, transferred to an airtight container, and refrigerated for up to 2 days. Reheat gently before continuing.

Make the Crostini

Preheat the oven to 400°F (200°C). Brush both sides of the bread with olive oil and place on a baking sheet. Season lightly with salt and pepper. Bake for about 6 minutes, flipping halfway, until lightly toasted on both sides. Set aside.

Assemble & Serve

Preheat the broiler.

Place two oven-safe bowls on a baking sheet. Ladle the soup into the bowls, leaving about ½ inch of space at the top. Arrange the crostini in a single layer over the soup, trimming to fit if needed. Generously sprinkle with mozzarella and Gruyère, allowing a little cheese to spill over the edges.

Broil for about 5 minutes, watching closely, until the cheese is bubbly and golden brown. Let cool slightly before serving.

From the Heart

Serve this soup with a simple green salad and a glass of red wine for an effortless, cozy meal that feels special without being complicated — just the way cooking together should be.