Add broth, water, 1/4 teaspoon salt, 1/8 teaspoon nutmeg and 1/8 teaspoon pepper. Bring to a boil. Stir in egg noodles and peas. Reduce heat to low; cover and simmer 10 minutes or until egg noodles are tender and meatballs are thoroughly cooked, stirring occasionally. Stir in sour cream.