Cook vegetables with ½teaspoon salt in as little water as possible in a covered pot.
Strain and cool (broth may be saved to make vegetable soup).
Mix raw egg yolks with mustard, sugar, lemon juice, sour cream, and apinch of salt. Cook over very low heat or in the top part of a double boiler while whipping all the time. When the sauce starts bubbling, take it off the heat.
Add cooked vegetables, chopped apple and chopped pickle. Mix, and chill.
Put salad on a large serving platter and top with stuffed eggs.