Boil the sweet potatoes in water until just falling apart. Drain and mash until smooth.
Debone pilchards and flake. In a large bowl, mix together flaked pilchard, mashed sweet potatoes, onion, a tablespoon or two of sauce from the tin, freshly chopped parsley and the breadcrumbs.
Season with some salt and pepper to taste. The mixture should hold together well.
Form medium sized balls in your hands and press down to form patty shapes.
Crush the corn flakes and place in a shallow bowl. Dust each patty with flour, then dip into the egg, then crushed corn flakes.
Place on a tray and refrigerate for 15 minutes. Remove patties from the fridge.
Heat a tablespoon of oil in a shallow pan and fry patties for 10 - 15 minutes on either side, until golden and crispy.
Slice buns in half and lightly toast them in the hot pan.
Remove and spread a generous amount of mayonnaise inside each half.
Pile some fresh rocket, your pilchard patty and cucumber ribbons on top of each other.
Finish with a drizzle of sweet chilli sauce and enjoy!
