Place diced vegetables on a large sheet pan lined with foil and sprayed with non-stick spray.
Cook at 500 degrees for 40 minutes or until browned.
Add cooked vegetables to a large pot. Add remaining ingredients and simmer for 30 minutes. Puree using an immersion blender. Add additional liquid if you desire a thinner soup.
Pour into individual serving bowls or cups. Add a small amount of half and half to each serving, if desired.
Note: if you use a blender or food processor to puree, do it in small batches.