Panino with Secret Purple Sauce

Method

1. Dice the purple potatoes and red onion coarsely. Cook in a pan with some butter until lightly roasted, then add a splash of water and salt, and continue cooking.
2. Prepare the batter: mix equal weight of all-purpose flour and rice flour. Add equal amounts of sparkling water and beer, stirring until a thick batter forms. Add some paprika. Let rest for 15 minutes if possible.
3. Prepare the sauce: in a bowl, mix Greek yogurt, chopped olives, desalted capers, mint leaves, grated lemon and lime zest, pepper, and a pinch of salt. Mix well. Do not add lemon juice.
4. Cut the cod into squares. Heat oil to 170-180°C. Dip the fish pieces in the batter and fry until golden and crispy. Drain and sprinkle with some paprika.
5. Toast the multigrain bread in a dry pan.
6. Assemble the sandwich: spread a generous layer of sauce on the bread. Add the roasted purple potatoes, then the fried fish. Top with more lemon and lime zest. Close the sandwich.
7. If frying for many people, pre-fry the fish for 2-3 minutes and then refry at 180°C for the last minute for a freshly fried result.