Roasted Garlic Onion Soup (Printable version)

A flavorful blend of roasted garlic, caramelized onions, and herb croutons in a rich, comforting broth.

# 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 & Oils

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

→ Liquids

08 - ½ 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 - ½ teaspoon dried oregano
14 - Salt and black pepper to taste

→ Herb Croutons

15 - 3 cups day-old baguette, cut into ¾-inch cubes
16 - 2 tablespoons olive oil
17 - 1 tablespoon fresh parsley, chopped
18 - 1 teaspoon dried thyme or Italian herbs
19 - ¼ teaspoon garlic powder
20 - Pinch of salt

# Directions:

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 - While garlic roasts, 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, fresh parsley, dried thyme, 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 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.

# Expert Advice:

01 -
  • The roasted garlic turns into silky, spreadable sweetness—nothing sharp or bitter about it.
  • Those crispy herb croutons are genuinely addictive and save you from having to buy expensive bread at the soup course.
02 -
  • Caramelizing onions can't be rushed—low and slow is the only way, and if you crank the heat to save time, you'll get brown instead of caramel and the whole thing tastes burnt.
  • Don't skip removing those thyme sprigs and bay leaf before serving, because biting into a tough stem or bay leaf leaf will completely derail an otherwise perfect bowl.
03 -
  • Make your croutons while the soup simmers so everything finishes at the same time, and use them the same day while they're still crisp—storing them in a sealed container makes them go soft.
  • If you're feeding people with different dietary needs, you can easily make a vegan version by using only olive oil and doubling the quantity, so you lose nothing in richness or flavor.
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