1 Make the matzo ball mixture: Make the matzo ball mixture: In a medium mixing bowl, whisk together the eggs, schmaltz, water, salt, and pepper. Stir in the matzo meal.
Cover the bowl tightly and chill it in the fridge for at least two hours, or up to a day ahead.
2 Shapeand cookthe matzo balls: In a large saucepan or soup pot, bring 3 quarts of water and 1 1/2 teaspoons of salt to a boil. When the water is boiling, turn the heat down to medium-low.
Use your hands to roll the matzo ball mixture into approximately 1-inch balls. As you finish rolling each ball, gently drop it into the simmering water.
When all of the matzo balls are in the water, immediately cover the pot and reduce the heat to low. Let the matzo balls simmer, covered, for 40 minutes, until they have floated to the top and roughly doubled in size. Avoid uncovering the pot while the matzo balls are cooking (a covered pot helps the matzo balls cook more evenly and quickly).
3 Warm the broth and vegetables: While the matzo balls are simmering, bring the chicken broth up to a simmer in a medium (3-quart) saucepan over medium heat. Add the sliced carrots and celery and reduce the heat to low.
Simmer the vegetables in the broth until they’re tender, about 5 minutes. Turn off the heat and keep the broth covered so it stays hot while the matzo balls finish cooking.
4 Serve the soup: Use a slotted spoon to transfer three matzo balls into each soup bowl, then ladle 1 1/2 cups of broth into each bowl. Garnish each bowl with a sprinkle of parsley or dill and a few grinds of black pepper. Serve piping hot.