In a large bowl, whisk eggs and schmaltz (or oil) together.
Add matzo meal, salt, pepper, and dill (if using). Mix well.
Gradually stir in seltzer water until the mixture is uniform.
Cover and refrigerate for 20-30 minutes (helps firm up the dough).
Bring a large pot of salted water or chicken broth to a gentle boil.
Wet hands and roll the dough into 1-inch balls (don’t over-handle; they expand while cooking).
Drop matzo balls into boiling liquid, reduce heat to a simmer, cover, and cook for 20-25 minutes (don’t lift the lid!).
In a separate pot, sauté onions, carrots, and celery in a bit of oil until softened (~5 mins).
Add garlic, broth, salt, and pepper. Simmer for 15 minutes.
Gently transfer cooked matzo balls into the soup. Heat through for 2-3 minutes.
Ladle soup into bowls, garnish with fresh herbs, and enjoy!
