Heat olive oil in a large pot on the stovetop over medium-high heat. Add garlic, onions and a pinch of salt and sauté until onions are soft and translucent, about 8 minutes.
Pour the 8 cups of vegetable broth into the pot and bring to a boil.
Slowly add the broccoli and reduce the heat to medium. Add another pinch of salt and pepper to the pot and cook the broccoli for 8 minutes until slightly tender.
Add the spinach and kale in small amounts slowly to the soup. Allow the leaves to wilt slightly before adding more.
Add the basil leaves, cover pot and simmer soup for 20 minutes.
Working in batches, add the soup mixture to a high-powered blender or food processor and blend until soup is pureed. Do not to overload the blender or food processor and be careful as the soup will be hot.
Serve immediately in soup bowls or freeze for later. When serving, add basil leaves or chopped tomatoes as a garnish. Enjoy!