Wash fish fillets, pat dry and cut into about 3-4 inch / 8-10 centimeter pieces. Sprinkle with salt and pepper.
Break an egg into one dish, add a tablespoon of water and scramble. Place flour in another dish. Heat oil in a non-stick frying pan. Dip each piece of fish in egg, then flour and sauté on medium until cooked and lightly golden brown. Remove and place on a paper towel.
Peel carrots, parsnip, and celery root and grate on the largest side of a vegetable box grater. Chop onion. Heat oil and butter in a wide pan / deep frying pan and add peppercorns, allspice berries, and bay leaves, followed by shredded vegetables and onions. Heat through. Add broth, tomato paste, salt and pepper, and paprika. Sauté until cooked, about 5-7 minutes. Don't overcook, leave a bit of crunch in the veggies.
Taste. Add a bit more salt, if needed.
Once veggies are cooked, create layers in a serving dish by placing about ⅓ of the veggie mixture first, then arrange fish pieces and cover with the rest of the veggie mixture. Cover with foil and let cool.
Refrigerate until serving.
