Preheat your oven to 400°F (200°C). Take the unpeeled garlic cloves, drizzle them with olive oil, wrap them in foil, and place on a baking sheet. Roast for about 30 minutes until golden brown.

While the garlic is roasting, heat olive oil in a large pot over medium heat. Add chopped onion, stirring until translucent, about 5-7 minutes.

Once the garlic is roasted, squeeze it into the pot. Pour in the broth and add thyme. Bring to a gentle simmer for about 2 minutes.

Reduce heat to low and let the soup simmer for 15-20 minutes, stirring occasionally.

Remove thyme sprigs and use an immersion blender to purée the soup until smooth.

Stir in heavy cream, season with salt and black pepper to taste, and warm through for an additional 5 minutes.

Ladle the soup into warm bowls and garnish with fresh herbs or croutons. Serve it alongside warm crusty bread.