Sift the flour. Add the rest of the products and knead a soft dough. Put the dough in a buttered bowl and cover it with plastic wrap. Leave it in a warm area to double in volume.
Knead the dough again and roll it out into a sheet. Put it in an oven dish with a buttered bottom. Let it rise once again.
Peel the onions and leeks and cut them into small pieces. Heat the oil and saute the vegetables until they take on a golden crisp.
Let them cool and distribute the filling on top of the dough. Add the drained red beans as well.
Sprinkle with dried parsley and sea salt and bake in a preheated oven until golden.