1. Make the matzo balls: In a large bowl, whisk together eggs, oil, salt, and pepper until well combined. Add matzo meal and seltzer; mix to combine. Cover and refrigerate for 1 hour.

2. Make the soup: Heat oil in a Dutch oven over medium-high heat. Add onion, celery, carrot, sweet potato, parsnips, ginger, and garlic; cook, stirring, until lightly browned, about 2 minutes. Add water or broth, bay leaves, and thyme; reduce heat and let simmer until vegetables are tender, about 45 minutes. Do not let liquid come to a boil. Remove from heat; strain and discard solids. Add dill and season with salt and pepper. Keep warm until ready to serve.

3. Bring a large pot of water to a boil. Line a baking sheet with wax paper and set aside.

4. Moisten hands with water and, using your hands, form matzo batter into about 1 1/2-inch balls. At this point, matzo balls can be transferred to freezer until frozen and then transferred to airtight containers and kept frozen for up to 1 month. Frozen matzo balls can be added directly to boiling water.

5. Place matzo balls in boiling water; cover and cook until light and fluffy, about 20 minutes. Carefully transfer matzo balls to warm soup; serve immediately.