Preheat the oven to 190°C.
Prick potatoes with a fork and bake for 60 minutes until tender.
Mash potato flesh until smooth, season, and let cool.
Mould mashed potato around cheese pieces to form small sausages.
Coat sausages in flour, beaten egg, and breadcrumbs then chill for 30 minutes.
Heat vegetable oil in a deep saucepan until shimmering.
Deep fry croquettes for 3 minutes until golden and drain on paper.
Combine tomatoes, onion, capers, and parsley in a bowl.
Whisk vinegar and rapeseed oil together to make a dressing.
Dress the tomato mixture and salad leaves separately.
Serve croquettes immediately with both salads.