Trim white asparagus, if using, with vegetable peeler, from just under tip to stem end to remove woody skin. If using green, trim just hard stem end.
Bring large pot of salted water to boil.
Bundle asparagus up and tie with kitchen twine. Trim ends evenly. Gently place in boiling water and immediately lower heat to simmer. If using white asparagus, cover pot. If using green, DO NOT cover, as it will lose it's fresh green color. Simmer for approximately 15-30 minutes, depending on thickness of stems. When tender, remove bundle and carefully drain on kitchen towel, being careful of tender tips.
Melt the butter over low heat in a small saucepan. If the eggs are completely cold, plunge into hot asparagus water for 1 minute. Remove, dry and peel.
In a small bowl, mash the complete egg with a fork. Add the melted butter, lemon juice, parsley, nutmeg and salt and pepper. Mix thoroughly.
Arrange the asparagus on individual plates. Pour Flemish sauce to cover all but the tips of the asparagus. Serve immediately while everything is still warm.