Polish Fish with Vegetable Topping (Ryba Po Grecku)

for the fish:

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

for the vegetable topping:

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