Heat olive oil in a large pot over medium heat. Add chopped onions and sauté until they become translucent, about 5 minutes. Stir in minced garlic until fragrant, around 1 minute more.

Add chopped broccoli florets and diced potatoes to the pot. Cook for an additional 5 minutes, stirring occasionally.

Pour in the low-sodium vegetable broth, ensuring the vegetables are covered. Bring to a boil, then reduce heat and simmer for about 15-20 minutes, or until the potatoes are tender.

Blend the mixture until smooth using an immersion blender or by transferring to a standard blender.

Return the blended soup to low heat and stir in the heavy cream. Let it simmer gently for another 5 minutes, stirring occasionally. Season with salt and pepper to taste before serving.