Polish Fish with Vegetable Topping (Ryba Po Grecku)

for the fish:

• 1 1/2 pounds (680g) white fish fillets, such as cod
• salt and pepper to taste
• 1 teaspoon oregano
• 1 teaspoon thyme
• 1/2 teaspoon paprika
• 1/4 cup (30g) flour
• 1/4 cup (60ml) frying oil

for the vegetable topping:

• 1 tablespoon Frying oil
• 3 medium carrots 200g
• 2 parsley roots 100g
• 1/2 leek the white part
• 1 medium onion
• 3 ounces (85g) celeriac or 1 celery rib and more carrots/parsley root
• 2 cloves garlic
• 1/2 teaspoon paprika
• 1/2 teaspoon basil
• 1/2 teaspoon thyme
• 2 bay leaves
• 2 allspice berries optional
• 1 cup water or vegetable/chicken broth
• 3 tablespoons tomato paste
• 1 teaspoon lemon juice
• 1/2 tablespoon chopped parsley
• salt and pepper to taste