Roasted Garlic & Sweet Onion Soup
This Roasted Garlic & Sweet Onion Soup is a rich, velvety blend of caramelized sweet onions, silky roasted garlic, and leeks, all simmered in a white wine–infused broth and finished with a splash of milk. Garnished with fresh thyme and cracked black pepper, it’s the ultimate cozy bowl for any chilly evening.
Ingredients
- 1 large whole garlic head
- 1 ½ tablespoons olive oil divided use
- 9 cups about 4 large thinly sliced sweet onions
- 2 ½ cups about 2 medium sliced leeks (light green and white parts only)
- 1 teaspoon salt divided use
- 1 teaspoon dried thyme
- 2 tablespoons all-purpose flour
- ⅓ cup dry white wine
- 4 cups vegetable broth
- 2 cups milk
- Fresh thyme leaves for garnish
- Freshly ground black pepper for garnish
Instructions
- Preheat oven to 350°F. Rub garlic head with ½ tbsp olive oil and wrap in foil.
- Bake 1 hour, cool, peel cloves, and set aside.
- Heat 1 tbsp olive oil in a large pot over medium heat. Add onions and leeks.
- Cook uncovered, stirring often, for 30 minutes.
- Add ½ tsp salt and thyme. Cook another 30 minutes.
- Stir in flour and cook 1 minute. Add wine and broth.
- See full steps with tips & photos → https://wimpysdiner.net/roasted-garlic-and-sweet-onion-soup/
Notes
- Flavor Boost: Use a splash of sherry instead of white wine for deeper complexity.
- Make-Ahead: Caramelize onions and roast garlic up to a day ahead; refrigerate and assemble before reheating gently.
- Dairy-Free Option: Swap milk for unsweetened almond or oat milk and use dairy-free butter.