Whisk flour, salt, eggs, milk, water, and melted butter into a smooth batter.
Heat oil in an 18cm frying pan and swirl in two tablespoons of batter.
Cook for 30 seconds, flip, cook for 20 seconds, and stack between greaseproof paper.
Preheat the oven to 180°C.
Sauté sliced leeks in butter for 5 minutes until softened.
Mix drained leeks with smoked cheese, herbs, peas, and ricotta.
Spread filling onto pancakes and roll into cylindrical shapes.
Coat each roll in flour, then beaten egg, then polenta.
Fry rolls until golden, then bake in the oven for 12 minutes.
Mix onion, cucumber, tomatoes, passata, chilli, and vinegar for the salsa.
Serve the hot pancake rolls with the salsa on the side.