Put a large stockpot over a medium flame and heat the oil. Add the carrots, onions and celery and cook until the onion is translucent and the vegetables are soft, about 5-7 minutes.
Add the tomatoes to the pot and cook until softened, about 3-5 minutes.
Add the water and bouillon cubes and raise the heat to high. Bring to a boil and add in the squash and zucchini. Cook for 5 minutes and add in the riced cauliflower. Cook until the squash, Zucchini and cauliflower are tender, about another 5 minutes.
Serve with crusty bread or Taralli and a generous sprinkle of grated Pecorino cheese!