In a large pot over medium heat, melt butter or olive oil. Sauté chopped onions until translucent (about 5 minutes), then add minced garlic and cook for an additional minute.

Add the broccoli florets and diced zucchini to the pot; sauté for 3-4 minutes until slightly softened.

Pour in the vegetable broth, bringing it to a gentle boil. Reduce heat and simmer for 15-20 minutes until vegetables are tender.

Blend the mixture until smooth using an immersion blender or in batches with a regular blender.

Return the blended soup to low heat. Stir in heavy cream (or coconut milk) and crumbled blue cheese until melted. Season with salt and pepper to taste.

Serve warm, garnished with extra blue cheese crumbles or herbs if desired.