In a large soup pot over high heat, heat the olive oil and soften the onion and garlic but do not allow them to brown. Add the potatoes, then the sea salt, pepper flakes, and greens, stirring well. Add the water and bay leaf and simmer 15 minutes, or until potatoes are tender. Discard bay leaf.
Serve in large bowls with bread alongside and cheese grated over the top.
Recipe copyright Mario Batali, 2002. All Rights Reserved.