1. Heat the olive oil in a large pot or Dutch oven over medium heat. Add the chopped onion and cook, stirring occasionally, until softened and translucent, about 5-7 minutes.

2. Stir in the minced garlic and cook for another minute until fragrant. Be careful not to burn the garlic. Then, add the broccoli florets to the pot.

3. Pour in the vegetable broth, ensuring the broccoli is mostly submerged. Bring the mixture to a boil, then reduce the heat to a simmer, cover the pot, and cook for 10-15 minutes, or until the broccoli is very tender and easily pierced with a fork.

4. Carefully transfer the soup in batches to a blender, or use an immersion blender directly in the pot. Blend until the soup is completely smooth and creamy. If using a regular blender, make sure to vent the lid to allow steam to escape and avoid pressure buildup.

5. Return the blended soup to the pot (if you used a regular blender). Stir in the heavy cream and fresh lemon juice. Heat gently over low heat for 2-3 minutes, just until warmed through. Do not boil after adding the cream, as it can curdle.

6. Season the soup with salt and black pepper to taste. Give it a final stir and ladle into bowls. Garnish with a sprinkle of fresh herbs or a swirl of extra cream if desired.