Put flour and salt into a large bowl and create a well in center. Pour eggs into the well. Wet hands and knead the mixture into dough. Add water, and continue kneading until dough is smooth.

Roll dough into ball and place it in a bowl. Cover bowl with damp cloth and refrigerate 30 minutes.

Using a floured rolling pin and a well-floured board, roll dough to paper-thinness (as much as possible). Cut dough into 2-inch (5-cm) squares (you can roll each square a bit thinner at this point).

Sauté onion in oil until nicely browned. Add chicken and mix well. Let cool and then pour into bowl. Add the rest of the ingredients and mix.

Place a flatware teaspoon-worth of filling in center of dough square. Fold it diagonally to create a triangle. Seal the sides with a beaten egg. Fold the two corners into the center until they meet.

Bring a pot of water to a vigorous boil. Add one tablespoon salt, carefully drop kreplach into pot, and cook for 20 minutes.

Serve kreplach in chicken soup.