Roasted Garlic Onion Soup (Printable version)

Comforting soup with roasted garlic, caramelized onions, and crispy herb croutons in a savory 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 & 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

# 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. Allow to cool, then squeeze roasted garlic from skins and reserve.
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, until onions are deeply caramelized and golden brown, approximately 25–30 minutes.
03 - Deglaze the pot with white wine, scraping up all browned bits from the bottom. Simmer until liquid is reduced by half, approximately 5 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 or Italian herbs, garlic powder, and salt. Spread on a baking sheet and bake at 400°F for 10–12 minutes, stirring once, until golden and crisp.
06 - Taste soup and adjust seasoning as needed. For a smoother texture, blend part or all of the soup using an immersion blender.
07 - Ladle soup into bowls and top with generous handfuls of herb croutons. Garnish with fresh parsley if desired.

# Expert Tips:

01 -
  • Deep, complex flavor from roasted garlic and caramelized onions that develops over slow cooking
  • Vegetarian-friendly but so rich and satisfying it feels indulgent
  • The homemade herb croutons add irresistible crunch and aromatic freshness
  • Versatile base that can be customized with cheese, different herbs, or made fully vegan
  • Makes your kitchen smell absolutely incredible while cooking
02 -
  • Roast extra garlic heads and store the squeezed cloves in olive oil for easy use in other recipes
  • The soup tastes even better the next day as flavors continue to meld—store croutons separately to keep them crispy
  • Use a mandoline to slice onions uniformly for even caramelization
  • Add a splash of heavy cream or coconut cream at the end for extra richness
  • Freeze leftover soup in portions for quick weeknight meals—just make fresh croutons when ready to serve
Go back