1. In a bowl, whisk together eggs, seltzer, oil, salt and pepper until well combined. Add matzo meal and stir thoroughly. Refrigerate for 1 hour.
2. Fill a large pot halfway with water and bring to a boil. Moisten palms with cold water and form matzo mixture into 1-inch balls. You should get about 16 balls. Carefully drop them into the boiling water and reduce heat to low.
3. Simmer covered until the matzo balls are cooked and puffed, about 30 minutes. Remove with a slotted spoon to a large bowl.
4. In a large saucepan, bring chicken broth, diced onion, sliced carrots and sliced celery to a boil. Lower heat and add matzo balls. Simmer for 15 minutes, or until vegetables are cooked.
Per serving: 199 calories, 11g fat, 2g saturated fat, 126mg cholesterol, 695mg sodium, 16g carbohydrate, 1g fiber, 2g sugar, 9g protein