Image credit to: Boston Organics
Preheat oven to 425 degrees. Toss vegetables, including garlic cloves, with olive oil and salt and pepper. Spread vegetables in an even layer on a lined baking sheet or dish and place in oven. Roast for 20 minutes.
After 20 minutes, stir vegetables and turn heat down to 400 degrees. Roast for another 20 to 30 minutes, stirring every 10 minutes, until very tender and caramelized on the edges. Remove from the oven. You should have about 4 cups roasted vegetables.
Place one garlic clove, half the vegetables and 2 cups of the stock in a blender. Cover the top of the blender with a towel pulled down tight (don't use an airtight lid because hot mixture will jump and push the top off and make a dangerous mess).
Blend until smooth and transfer to a soup pot. Repeat with the second half of the roasted vegetables and another 2 cups of broth. Transfer to the pot and whisk in remaining broth. Season to taste with salt and pepper and heat through. Serve each bowl with a sprinkle of chopped fresh herbs and, if you wish, a swirl of crème fraîche or yogurt.