Make the dough: In a large mixing bowl, add the flour and salt and mix until combined. Add the eggs and water, and mix with a fork until combined. Form the dough into a ball, and on a well-floured knead for about 5 minutes, or until the dough becomes soft and elastic. Form it into a smooth ball, return it to the bowl, and rest under a damp cloth for 30 minutes.

Make the filling: Heat the schmaltz in a skillet over medium heat. Add the onion, garlic, and salt, and cook until translucent, about 5 minutes. Remove from the heat.

In a food processor, combine the turkey or chicken with the onion mixture, making sure to include as much schmaltz as possible. Pulse about 8-10 times until well combined. Transfer to a mixing bowl and add the chopped dill, if using, and mix well until fully combined. Cover and chill in the refrigerator until ready to assemble.

Divide the dough ball into 4 equal portions. Roll each portion into a ball, keeping the others covered with a towel while you work. Working one at a time, create a hole in the dough ball with your thumbs so that it looks like a bagel. Begin stretching out the loop of dough until the width of the dough is about ¾-inch thick. Cover the piece of dough with a kitchen towel and repeat this process with the other 3 pieces of dough.

Take each dough loop and cut it at two opposite points, creating two straight logs. Roll each log with your hands until it is about ½ inch thick. Cut the logs into 1-inch pieces, cover them with a towel, and repeat with the remaining three loops.

Working one small piece of dough at a time, roll it into a small ball. Using your hands first, then a rolling pin, flatten the dough until it's round and thin, about 2-inches in diameter.

Place 1 heaping teaspoon of filling in the center of each dough circle. Fold the dough in half and pinch the edges firmly to seal, ensuring no filling escapes during cooking.

Bring the corners of the half-moons together, overlap them a bit and pinch to seal. Repeat with the rest of the dough pieces. Cover and chill until ready to cook.

To cook the kreplach, bring a medium saucepan of salted water to a boil. Add the kreplach and stir gently to prevent sticking. Cook for about 3 minutes (or 5 minutes if frozen), until al dente.

Serve the kreplach in hot chicken broth and garnish with more dill (optional). Kreplach can be stored in the refrigerator for 3–4 days in an airtight container.