Preheat oven to 400 degrees F.

Combine flour, potatoes, onion, salt, pepper and egg whites in a large bowl and stir until blended. Divide mixture into 48 level tablespoon sized pancakes, squeezing to remove excess moisture.

Heat half the olive oil in a skillet (you may need more to avoid sticking) over medium high heat. Add 16 pancakes; cook 3 minutes on each side or until browned. Arrange two baking sheets with paper towels and place pancakes to drain. Repeat the procedure with the remaining pancakes and oil.

Combine mayonnaise, apple, yogurt and horseradish in a small bowl. Set aside.

At this point you can place pancakes in a container between parchment paper and freeze for later or bake on lightly oiled baking sheets for 5 minutes, until cooked through.