Preheat your oven to 425 degrees.
Wash and prepare your vegetables. Place them on a large baking sheet lined with parchment paper.
Peel off a few of the papery outside layers of the garlic, then cut off about 1/2" of the top of the garlic bulb to expose the cloves. Season with a drizzle of olive oil and salt and pepper. Wrap it in tinfoil and roast in the oven with the vegetables.
Drizzle the olive oil over your vegetables and then sprinkle them evenly with the seasonings.
Roast the vegetables in the oven for 30 to 40 minutes or until they are tender and carmelized. You may need to remove some of them earlier if they are done as they may not all cook evenly.
Place the vegetables in a blender and squeeze in the roasted garlic. You may need to blend them in batches if the blender is getting too full. Blend the vegetables until they are smooth. Use either a blender or you may alternately use an immersion blender.
Pour the blended vegetables into a large Dutch oven type pan. Add the vegetable broth, stir, and bring to a boil. Add more or less broth if needed to desired soup consistency. Add more salt and pepper to taste if needed.
Add the milk or half and half into the soup and stir. Heat up the soup a little if needed but don't bring it to a boil.
Serve the soup in bowls topped with fresh basil or parsley if desired.
Any leftover soup may be stored in the refrigerator for up to five days. It could also be frozen in a freezer safe container for up to three months.
Calories based on soup made with 2% milk.