Step 1: Preheat oven to 375°F (190°C). In a small oven-safe dish, toss the peeled garlic cloves with 1 tablespoon of olive oil. Cover tightly with foil and roast for 45-60 minutes, or until the garlic is very soft and caramelized. Remove from oven and set aside.
Step 2: While the garlic roasts, heat the remaining 1 tablespoon of olive oil in a large Dutch oven or heavy-bottomed pot over medium heat. Add the chopped onion, carrots, and celery. Sauté for 8-10 minutes, or until softened, stirring occasionally.
Step 3: Add the roasted garlic (it should be very soft and easily mashed), vegetable broth, fresh thyme, and bay leaf to the pot. Bring the mixture to a simmer, then reduce heat to low, cover, and let it cook for 20-30 minutes, allowing the flavors to meld.
Step 4: Remove the bay leaf. Using an immersion blender, carefully blend the soup until it’s completely smooth and creamy. Alternatively, transfer the soup in batches to a standard blender, blending until smooth. Be cautious when blending hot liquids.
Step 5: Return the blended soup to the pot. Stir in the heavy cream, if using, and heat gently for a few more minutes until warmed through. Do not boil after adding cream.
Step 6: Season generously with salt and freshly ground black pepper to taste. Ladle the warm 50 Clove Garlic Soup into bowls, garnish with fresh parsley or chives, and serve immediately with crusty bread or homemade croutons.