Remove stems from spinach; wash leaves thoroughly and tear into large pieces. Cook spinach in a small amount of boiling water for 5 to 8 minutes or until tender. Drain, place on paper towel and squeeze excess water until barely moist. Set aside. In a large skillet, sauté onion and garlic in butter. Stir in sour cream, salt, pepper and nutmeg. Add spinach and cook over low heat until thoroughly heated; sprinkle with paprika.