Roasted Garlic Onion Soup (Print Version)

Deeply flavorful soup with roasted garlic, caramelized onions, and aromatic herb croutons.

# Ingredient List:

→ 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 herb blend
19 - 1/4 teaspoon garlic powder
20 - Pinch of salt

# How-To Steps:

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 reserve.
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 reduces by half, approximately 5 to 7 minutes.
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, thyme, garlic powder, and salt. Spread on a baking sheet and bake at 400°F for 10 to 12 minutes, stirring once, until golden and crisp.
06 - Taste soup and adjust seasoning with salt and pepper. For a smoother texture, blend part or all of the soup using an immersion blender.
07 - Ladle soup into bowls and top with a generous handful of herb croutons. Garnish with fresh parsley if desired.

# Helpful Tips:

01 -
  • The roasted garlic becomes mild and almost buttery, so even garlic skeptics find themselves swooning over this soup.
  • Those crispy herb croutons give you a textural contrast that transforms a simple soup into something memorable.
  • It's the kind of dish that tastes like you spent hours in the kitchen, but honestly, most of the time is just letting the oven do the work.
02 -
  • Don't let the onions brown too fast over high heat—medium-low heat is your friend here, and those 25 to 30 minutes of caramelization are non-negotiable if you want that deep, sweet flavor.
  • The immersion blender is optional, but it changes the texture from rustic to something that feels almost velvety, so if you have one, it's worth pulling out.
03 -
  • Buy your baguette the day before you make the croutons so it's already stale and ready to crisp up properly instead of getting chewy.
  • If your garlic roasts faster than expected, wrap it loosely in foil so the heat doesn't intensify—overly charred garlic tastes bitter and loses all that buttery magic.
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