Salmon and Cod Fishcakes

Name: Salmon and Cod Fishcakes
Ingredients: 6 large potatoes cut into quarters; Salt and freshly ground black pepper; 1 stick butter, divided; 1 pound salmon; 1 pound cod; 3 tablespoons olive oil, for dipping fish; 1 tablespoon balsamic vinegar, for dipping fish; 2 shallots, finely chopped; 4 scallions, finely chopped; Handful chives, parsley, fennel and dill, finely chopped; 3 garlic cloves, finely chopped; 1 red chile, seeded and finely chopped; Flour; 3 tablespoons sunflower oil, for frying; Parsley sprigs and lemon slices, for garnish; Serving suggestion: green salad