Combine florets with oil; toss well. Add thyme and salt and toss well again. Arrange on a jelly-roll pan coated with nonstick spray. Bake at 400 1 hour or until golden brown, stirring after 30 minute.
Combine florets, 2 c broth, and milk in a blender. Process 3 min or til smooth. Pour pureed mixture into a large saucepan. Add remaining broth and pepper. Cover over medium until heated. Garnish with fresh parsley or fresh thyme, if desired.