In a large pot, heat a drizzle of olive oil over medium heat. Add the chopped onions and minced garlic, sautéing until the onion is translucent and fragrant.

Toss in the chopped cauliflower and pour in the broth. Bring the mixture to a boil, then reduce the heat and simmer until the cauliflower is tender, about 15 minutes.

Using an immersion blender, blend the soup until smooth. Alternatively, you can carefully transfer it to a blender, blend it in batches, and return it to the pot.

Stir in the heavy cream and season with salt and pepper to taste. Simmer for an additional 5 minutes, allowing the flavors to meld.

Ladle the soup into bowls and top with your choice of shredded cheese, chives, or croutons for extra flavor and texture.