Bring a saucepan of water to the boil, add spinach and simmer for 15 minutes or until soft. Drain well, squeezing to remove excess liquid, place in a bowl and cool. Pour over 1½ tbsp olive oil and lemon juice, season to taste with sea salt and black pepper and combine well.
Place spices in a mortar and, using a pestle, pound until finely ground. Combine spices and flour and season to taste. Coat fish, both sides, with spice mixture and leave for 2-3 minutes.
Heat 1½ tbsp olive oil in a large frying pan and cook fish, in batches if necessary, over medium heat for 5-7 minutes on each side or until golden and tender. Divide spinach among plates, top with fish and serve immediately with lemon wedges.