1. In a large bowl, mash the cottage cheese. Add egg yolks, half of the salt, the matzo meal, onion, sugar, sour cream, and pepper. Mix well.

2. With an electric mixer on high speed, beat egg whites with remaining half of salt until stiff. Fold a third of the egg whites into the cottage cheese mixture, then fold in remaining egg whites.

3. Heat a half-inch layer oil in a heavy frying pan, until a drop of water added sizzles. Form latkes into  thin patties (if batter/dough is too wet for your hands, shape with two tablespoons or spatulas).

4. Drop into oil and fry over a medium or medium-high heat until the undersides are golden brown. Turn carefully and brown the second side. Remove with slotted spoon and drain on paper towel. Serve immediately, or keep warm on a baking sheet in the oven.