This is the best easy classic French Onion Soup recipe of my life: rich, flavorful beef broth infused with buttery caramelized onion and herbs, topped with toasted baguette slices and gooey melted Gruyère cheese. Comfort food doesn't get any better. And it takes just 1 hour to make!
Add the oil and butter to a 5-quart Dutch oven over medium-high heat. Once the butter is melted, add the onion and stir to coat. Cook the onion until it is deep golden in color, about 30 minutes, stirring occasionally. Add a splash of water when it starts to stick to the pan, or when it starts to get too dark. Adjust the heat down as necessary so the onion doesn’t burn.
Once caramelized, stir in the garlic (if using), and cook 30 seconds, stirring constantly. Add the wine and cook until it’s mostly evaporated, using a wooden spoon to scrape up any brown bits from the bottom of the pan.
Add the salt, pepper, stock, thyme, and bay leaf, and bring up to a boil. Turn the heat down to a simmer, cover the pot, and let it cook for 10 to 15 minutes.
Meanwhile, preheat the broiler to toast the bread. Place the baguette slices on a broiler-safe baking tray and broil until both sides are golden, flipping once.
When the soup is done, remove the bay leaf. Ladle the soup into 4 broiler-safe crocks or ramekins. Place 2 slices of toasted baguette on each, and divide the cheese on top.
Put the crocks onto a broiler-safe baking tray and broil to melt the cheese. Serve.
Notes
If You Don't Have Broiler-Safe Crocks or Ramekins: Put the baguette slices onto a broiler-safe tray, sprinkle the cheese on top, and broil to melt the cheese. Place the cheesy toasts directly on top of the soup when serving.
What Kind of Wine to Use: Either a dry white wine or a dry red wine will work here. For whites, Sauvignon Blanc, Pinot Grigio, or Chardonnay are good options. For reds, Merlot, Pinot Noir, and Cabernet Sauvignon all work well.