03Place matzoh meal in a bowl, add fish stock and set aside.04Without washing food processor, add onions and process until finely chopped. Add fish and process until smoothly pureed. Add softened matzoh meal, eggs and remaining parsley and process until well blended. Season with salt (about 1 teaspoon) and liberally with pepper. Taste mixture for seasoning by poaching a small amount in water, then allowing to cool briefly.05Preheat oven to 350. Lightly oil a 6-cup loaf pan or ring mold.06Spread half the fish mixture in the pan, making a depression in middle that extends to within about 1/2 inch of sides. Spread half the leek mixture in depression; spread carrot puree over leeks and top with rest of leeks. Smooth in remaining fish. Rap pan several times on counter top to eliminate air holes. Place wax paper or parchment paper on top of the terrine.07Set the pan in a larger pan at least 2 inches deep and place in oven. Add 1 to 1 1/2 inches of boiling water to outside pan.08Bake 50 minutes.09Remove from oven and let cool. Remove fish loaf from pan and place on a serving dish. Cover with plastic wrap and refrigerate at least 6 hours to chill completely. Serve in slices with herbed or horseradish sauce on side.