Steam the cauliflower and blend half of it into a paste. Add salt, pepper and oregano, to make a ‘white sauce’. In a pan, sauté the leek until softened (add a little water if necessary). Add the white sauce and 1 cup of water and bring to a boil. Add the broccoli and the remaining cauliflower and season with basil. Take it off the heat once the sauce thickens slightly and the broccoli is tender. Sprinkle with broken bits of khakhra and serve.