Next level chicken burgers

Name: Next level chicken burgers
Ingredients: 2 large chicken breasts; sunflower oil for deep-frying; 2 tbsp smoked paprika; 2 tsp garlic granules; ½ tsp chilli powder; ½ tsp black pepper; 1 tsp dried oregano; 500ml buttermilk; 3 tbsp pickle juice from the gherkin jar (see ‘to serve’, below); 150g plain flour; 150g cornflour; 6 tbsp mayonnaise plus extra for the buns; 1-2 tbsp hot sauce (we used buffalo hot sauce); 4 slices burger cheese; 4 brioche burger buns; 4 medium gherkins sliced lengthways