Instructions:

1. In a large pot, melt the butter over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes. Add the minced garlic and cook for another minute.
2. Add the broccoli florets to the pot and pour in the chicken or vegetable broth. Bring to a boil, then reduce heat and simmer for about 20 minutes, or until the broccoli is tender.
3. Use an immersion blender or transfer the mixture to a blender in batches to puree until smooth.
4. Return the pureed soup to the pot and stir in the heavy cream. Heat over low heat until warmed through. Season with salt and pepper to taste.
5. If desired, garnish with grated cheddar cheese before serving.