Roasted Garlic Onion Soup (Print Version)

Comforting soup with caramelized onions, roasted garlic, and crisp herb croutons for rich flavors.

# What You'll Need:

→ Vegetables

01 - 3 large yellow onions, thinly sliced
02 - 2 whole heads garlic
03 - 1 large leek, white and light green parts, sliced
04 - 1 celery stalk, diced
05 - 1 medium carrot, diced

→ Fats & Oil

06 - 4 tablespoons olive oil, divided
07 - 2 tablespoons unsalted butter

→ Liquids

08 - 1/2 cup dry white wine
09 - 5 cups vegetable broth
10 - 1 teaspoon soy sauce, optional

→ Herbs & Seasonings

11 - 2 sprigs fresh thyme
12 - 1 bay leaf
13 - 1/2 teaspoon dried oregano
14 - Salt and black pepper to taste

→ Herb Croutons

15 - 3 cups day-old baguette, cut into 3/4-inch cubes
16 - 2 tablespoons olive oil
17 - 1 tablespoon fresh parsley, chopped
18 - 1 teaspoon dried thyme or Italian herbs
19 - 1/4 teaspoon garlic powder
20 - Pinch of salt

# How to Make:

01 - Preheat oven to 400°F. Slice tops off garlic heads, drizzle with 1 tablespoon olive oil, wrap in foil, and roast for 40 minutes until soft and golden. Cool slightly, then squeeze roasted garlic from skins and set aside.
02 - Heat 1 tablespoon olive oil and butter in a large pot over medium-low heat. Add onions, leek, celery, and carrot. Cook, stirring frequently, for 25 to 30 minutes until onions are deeply caramelized and golden brown.
03 - Pour white wine into the pot, scraping up browned bits from the bottom. Simmer until liquid is reduced by half.
04 - Stir in roasted garlic, vegetable broth, soy sauce if using, thyme sprigs, bay leaf, and oregano. Bring to a boil, then reduce heat and simmer uncovered for 25 minutes. Remove thyme sprigs and bay leaf.
05 - Toss bread cubes with 2 tablespoons olive oil, parsley, dried thyme or Italian herbs, garlic powder, and salt. Spread on a baking sheet and bake at 400°F for 10 to 12 minutes, turning once, until golden and crisp.
06 - Taste soup and adjust seasoning with salt and pepper. For smoother texture, blend part or all of the soup using an immersion blender.
07 - Ladle soup into bowls and top with generous handful of herb croutons. Garnish with fresh parsley if desired.

# Expert Advice:

01 -
  • The roasted garlic loses its bite and becomes creamy, almost like a subtle secret throughout the soup rather than an aggressive punch.
  • Those caramelized onions deliver the kind of rich, savory depth that makes you wonder where all that flavor was hiding in plain yellow onions.
  • Herb croutons add a textural moment that keeps every spoonful interesting, and they're proof that leftover bread belongs in this pot.
02 -
  • Don't rush the caramelization of onions—low, steady heat for 25 to 30 minutes beats high heat that burns the edges before the centers soften and sweeten.
  • If your roasted garlic seems stubborn to squeeze out, let it cool just a bit longer or run the head under warm water to loosen the skins.
  • Make the croutons on the same baking sheet and temperature as the garlic if timing is tight, but pull them out after 10 to 12 minutes so they don't over-bake while the soup simmers.
03 -
  • Make your croutons ahead of time and store them in an airtight container for up to three days—they'll stay crispy and you'll have one less thing to worry about when serving.
  • This soup actually tastes better the next day after the flavors have had time to settle and deepen, so don't hesitate to make it in advance and gently reheat it before serving.
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