In a large pot, heat the olive oil and butter together over medium high heat. Add the diced onion. Cook for 5 minutes until the onion becomes soft. Next, add the diced carrots and celery. Season with dried thyme and sage. and garlic powder. Allow to cook for an additional 5 minutes.
Into the pot, pour the chicken broth and the broccoli florets. Bring to a boil and allow the broccoli to cook for 15 minutes, until tender. Season with salt and pepper to taste. Using an immersion blender, puree half of the soup leaving some chunks of broccoli throughout.
For the dumplings, in a medium bowl, whisk together the flour, baking powder, parmesan salt, garlic powder and dried sage.
While the soup is boiling, drop 1 heaping tablespoon of the dumpling mixture into the soup, about 6-8 dumplings at a time. They may sink initially, but will rise as they cook. Cook the dumplings for about 10 minutes. Using a slotted spoon set the dumplings aside and repeat with any remaining dumpling batter. When the dumplings are done, add the heavy cream and cheddar cheese. Season to taste. Serve the soup with dumplings on top. Enjoy!