1. Combine turnip greens, bay leaf, lemon rind, instant chicken broth and boiling water in a large saucepan. Bring to boiling; lower heat; simmer 5 minutes. Cool a few minutes; remove bay leaf.
2. Pour into container of an electric, blender; cover; process at high speed until smooth; return to saucepan. Stir in evaporated skim milk; simmer over low heat until heated through; stir in salt, white pepper, nutmeg and yogurt.