800 gmskinless flathead fillets, cut into 10cm pieces1 tsphot smoked paprika½ tspcayenne pepperTo taste:finely grated rind of 1 lemon, plus lemon juice2 tbspolive oil2baby cos, torn1Lebanese cucumber, coarsely chopped½ cup(loosely packed) mint50 mlextra-virgin olive oil25 mlwhite wine vinegar, or to tasteTo serve:coriander cress (optional)Caper aïoli300 gm (1 cup)mayonnaise1golden shallot, diced¼ cupfinely chopped flat-leaf parsley2 tbspdrained capers in vinegar, finely chopped2garlic cloves, minced2 tspSherry vinegar, or to tasteFinelygrated rind and juice of ½ lemon, or to taste
For caper aïoli, combine ingredients in a bowl, season to taste and set aside.
Combine flathead in a large bowl with spices and lemon rind, season to taste and toss to coat well. Heat olive oil in a large frying pan over medium-high heat, add flathead and fry, turning occasionally, until browned and just cooked through (3-4 minutes). Dress with a little lemon juice and divide among plates.
Toss remaining ingredients in a bowl to combine, season to taste and serve with flathead and caper aïoli.