2 garlic cloves
1.5 teaspoons fresh thyme or oregano
juice of 1 lemon
1/2 teaspoon sweet smoked paprika (optional)
1 tablespoon olive oil
sea salt and black pepper

Crush the garlic and herbs in a mortar and pestle with a pinch of salt and pepper until smooth.
Add the lemon juice and paprika.
Rub all over the fish, then drizzle with the olive oil.
Leave to marinate in the fridge for 1-2 hours.