Spaetzle

1. Fill a large pot with water and bring to a boil over high heat.
2. Mix water, eggs, and salt together in a large bowl. Gradually stir in flour to make a stiff batter.
3. Scoop up some batter with a spoon and use another spoon to scrape it into the boiling water.
4. Repeat until several dumplings are cooking. Cook until dumplings float to the top, about 10 minutes.
5. Remove dumplings with a slotted spoon and drain in a colander or sieve.
6. Rinse with warm water and drain again. Repeat to make remaining dumplings.
7. Set aside and keep warm.

Chicken

1. Melt butter in a large skillet over medium-high heat.
2. Add chicken and cook until lightly browned, 3 to 5 minutes per side.
3. Add onion and cook until translucent, 5 to 8 minutes.
4. Pour in water and season with paprika, pepper and salt.
5. Continue to cook until chicken is no longer pink at the bone and the juices run clear, 10 to 15 more minutes. An instant-read thermometer inserted near the bone should read at least 165 degrees F.
6. Remove chicken from the skillet and keep warm.
7. Stir sour cream, tomato paste (if using) and flour together in a small bowl until well combined. Add to the skillet and slowly stir to combine with the sauce. Bring to a boil, stirring constantly, and cook until thickened, 2 to 3 minutes.
8. Spoon dumplings and chicken pieces onto serving plates. Ladle gravy over the top.
9. Place a generous dollop of sour cream on top of the chicken, if desired.