Mix the flour and salt. Add oil and enough warm water to form a soft dough, then knead for 8 minutes until smooth.
Divide into 6 balls, coat lightly with oil, cover, and rest for 1 hour.
Prepare the Filling and Sauce:
Cook the beef and onion over medium heat for 8 minutes. Add garlic, curry powder, cumin, and salt; cook for 2 minutes, then cool completely.
Simmer the passata, vinegar, sugar, chili flakes, and salt for 8 minutes, then set aside.
Combine the cooled beef with the eggs and scallions just before assembling.
Stretch and Cook:
On a lightly oiled surface, stretch one dough ball into a very thin rough square. Spoon one-sixth of the filling into the center and fold all four sides over it to make a flat parcel.
Heat a tablespoon of oil on the griddle over medium heat. Cook each parcel for 4 to 5 minutes per side until deeply golden and the egg is set. Rest for 2 minutes, then cut into squares.
Notes
Keep unworked dough covered so the surface does not dry out.
Cook over moderate heat so the filling sets before the thin bread becomes too dark.