1. Preheat oven to 400 degrees F (200 degrees C).
2. Rinse fish under cold water and pat dry with paper towels.
3. Brush cod with olive oil and season with salt and pepper on both sides. Spread a thin layer of mustard on the top of each fillet, sprinkle with parsley and paprika.
4. Transfer to a baking sheet, previously covered with aluminum foil. Bake in the preheated oven for 15-20 minutes, until flakes easily with a fork.