Add everything to a high-speed blender (like a Vitamix or similar) and blend on high for 7 minutes until the soup is hot and steaming. If you want a completely smooth soup, add the 1/3 cup florets along with everything else. But if you want some broccoli solids, add the 1/3 cup florets after blending for 7 minutes. Pulse them in on a low speed to mix them in and then serve the soup hot.