Preheat oven to 450 and place oven rack in center position.
Place florets, shallots and garlic gloves on parchment paper, drizzle with olive oil, toss making sure everything is covered in oil
Generously sprinkle with sea salt and pepper. Toss again.
Place in oven and roast for 30 minutes (or until golden), turning with spatula every ten minutes. Remove from oven.
Reserve two cups of cauliflower for later. You may need to do this next part in two batches of your blender is small: Place the remaining cauliflower, garlic and shallots into a blender.Add 3 cups of broth to blender (reserve the last cup for later)
Blend until smooth. Pour into a stock pot and place on medium heat.
Add milk, half and half or non dairy milk to pot. If using almond milk you may need less than recipe calls for as almond milk is somewhat thin. Whisk until smooth while continuing to heat.
If needed, thin with remaining broth and add more sea salt or pepper.
Chop reserved cauliflower. When hot, spoon soup into bowls, add remaining chopped cauliflower florets to top the soup, garnish as desired (see suggestions above)