In a large pot, melt butter over medium heat and sauté the onion until soft.
Add garlic and cook for about a minute until fragrant.
Toss in the chopped broccoli and pour in the vegetable broth.
Bring it all to a gentle simmer and cook for about 15 minutes until the broccoli is tender.
Use an immersion blender to puree the soup until smooth or leave it slightly chunky if you like texture.
Stir in the cream, cheddar, and parmesan, letting the cheese melt completely.
Season with salt, pepper, and a hint of nutmeg.
Serve hot with a sprinkle of extra cheese on top.