Combine water & broth in a large saucepan; bring to a boil. Add cauliflower; return to a boil. Reduce heat & cook 10 min. Or until tender. Remove cauliflower from broth, reserving broth. With knife blade in processor, add cauliflower. Pulse 8 to 10 times or until cauliflower is finely chopped, but not pureed.
Combine milk powder, flour, nutmeg, & pepper; add to reserved broth, stirring well with a wire whisk. Add chopped cauliflower & bring to a boil; reduce heat & simmer 15 min. Or until slightly thickened.
Ladle soup into 6 individual bowls; garnish with minced parsley if desired. Serve with lemon wedges.