*Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
**Nutrient information is not available for all ingredients. Amount is based on available nutrient data.
(-)Information is not currently available for this nutrient. If you are following a medically restrictive diet, please consult your doctor or registered dietitian before preparing this recipe for personal consumption.
Heat butter in a stockpot over medium heat; cook and stir leek and spinach until leek is tender, 5 to 10 minutes. Stir flour into leek mixture and cook over medium-high, stirring constantly, until mixture flour is dissolved, about 2 minutes. Remove stockpot from heat.
Mix broth, ham, and ham bone into leek mixture; cook, stirring occasionally, over low heat until soup is slightly thickened, about 15 minutes.
Blend yogurt, egg yolks, salt, and pepper together in a blender or food processor until smooth; carefully stir into soup. Cook soup until heated through, about 5 minutes more. Remove and discard ham bone.