• ¹\³  cup carrots, scraped and diced
• ¹\³ cup parsnips, peeled and diced
• 3 tbsp matzoh meal
• 2 tbsp mild olive or vegetable oil
• 1½ cups onions, coarsely chopped
• Salt and freshly ground pepper
• 1 tbsp chopped shallots
• 2 tbsp chopped fresh dill, plus 16 additional sprigs of dill
• 2 pounds fish fillets, skin and any bones removed and discarded (either have the fish ground by your fishmonger or rinse it to remove any scales, pat dry, and cut into 1-inch pieces).
• 2 large eggs 
• 2 large egg yolks
• 2 tbsp fresh lemon juice

• 1 cup mayonnaise
• ¹\³ cup finely minced dill
• ¹\³ cup plus 1 tablespoon prepared white horseradish, drained

About 12 large cabbage leaves, washed (the cabbage bed is discarded before serving, so you can use slightly imperfect or dark green outer leaves)

Soft lettuce leaves, endives, or radicchio for lining plates

1. Prepare the fish balls. In a small saucepan, bring one cup lightly salted water to a boil. Add the carrots and parsnips, and simmer until the vegetables are very tender. Drain, reserving the cooking water, and transfer the vegetables to a food processor. Put the matzoh meal in a small bowl and stir in ¹\³ cup of the reserved cooking water. Let this mixture sit so that the matzoh meal can soften as it soaks in the liquid.
2. Warm the oil in an 8-inch skillet. Add the onions, sprinkle them lightly with salt and pepper, and sauté, stirring, over medium heat until soft, shiny, and just beginning to color palest gold, 8-9 minutes. Don't let them brown. Transfer the onions and any oil remaining in the skillet to the food processor. Add the shallots and the chopped dill to the food processor and puree until fairly smooth. Transfer the mixture to a large wooden chopping bowl or a wooden chopping board. (Don't wash out the food processor if you are grinding your own fish). If your fish in not ground, put it, about 2 tsp salt, and ¹\8 tsp pepper in the workbowl of the food processor and pulse just until the mixture is chopped fine, but not pasty. Add the fish to the wooden bowl or board. (If you are using preground fish, add it now, seasoned with salt and pepper.) Add the soaked and softened matzoh meal mixture. Beat the eggs and the yolks in a bowl until thick and lemon-colored. Using a hand chopper or a cleaver, work the beaten eggs and the lemon juice into the fish mixture, a little at a time. (Hand-chopping at this point incorporates air into the mixture, making it lighter and fluffier than pulsing in the food processor.)
3. Test for seasoning. Poach a tsp of the fish mixture in lightly salted boiling water for a few minutes. Taste, and if needed, add additional salt and pepper. Chill the fish mixture, covered, for at least 1 hour or up to 4 hours. It will be easier to mold and the fish balls will cook up fluffier. 
4. While the fish is chilling, combine the ingredients for the dill-horseradish mayonnaise. Cover and refrigerate.
5. Steam the fish balls. You'll need a large, wide pot, like a 5-6 quart Duch oven or heavy casserole with a tight-fitting lid, and a rack that stands at least 2 inches high. A simple round cake rack works well. If it is not high enough, set it over 2 custard cups or empty tuna cans in the pot. Fill the pot with water to a depth of 1 inch.
6. Line the rack with a layer of cabbage leaves. Wetting your hands with cold water if necessary, form the fish mixture into 16 ovals, using a scant ¼ cup for each. Depending on the variety of fish used, the mixture may be very soft, but it will firm up as it cooks and later, as it chills. Bring the water in the pot to a boil. Gently put as many ovals on top of the cabbage leaves as will fit comfortably in a single layer without touching. Place a sprig of dill on each fish oval. Top the fish with another layer of cabbage leaves and cover the pot tightly. Turn the heat down to medium and steam the fish ovals for 20-25 minutes, or until they are completely cooked through at the center. (When steamed in raw cabbage leaves, the fish will probably take closer to 25 minutes; when steaming the second batch in the now cooked cabbage leaves, it will probably take about 20 minutes). Line a platter with some of the cooked cabbage leaves and carefully put the cooked fish on top of them. Using additional cabbage leaves as needed, cook any remaining fish ovals in the same way, transferring the fish as it is done to the cabbage-lined platter. Remove and discard the dill sprigs from all the cooked fish ovals, then cover the fish with a layer of cooked cabbage leaves to keep them moist. Let everything cool to room temperature. Wrap the platter with plastic wrap and chill the fish until cold.
7. For best flavor, serve the fish chilled but not icy cold. Remove the fish from the cabbage leaves and arrange the ovals attractively on platters or individual plates lined with lettuce, endive, or radicchio and accompany with dill-horseradish mayonnaise