Cook waffle fries according to package directions. Keep warm. Heat ham and keep warm.
To poach eggs, bring about 1 cup water to a boil in a small fry pan. Reduce heat to medium low. Add vinegar. Gently drop in eggs one at a time. Spoon hot water over eggs to shorten cook time. Cook until opaque, about 3 minutes.
sauce
Put yolks, lemon juice and salt in a blender. Puree until lemon yellow and thick, about 1 minute. While blender is running, slowly drizzle in melted butter. Mix until thick and smooth.
Plate fries. Top with ham and poached eggs. Drizzle with sauce. Sprinkle with parsley if desired.