Mix the butter with the flour until it becomes like crumbs. Add water and knead a smooth dough, and if necessary, add more water or flour. Wrap the dough in foil and put it in the refrigerator while you make the filling.
Heat oil in a wide frying pan and fry the crushed onions and leeks, then add some grated carrots and parsnips. When everything is tender, add the minced meat and stir vigorously until it fries a bit. Finally, season it with salt and pepper.
Remove from the heat and mix the filling with the cream. Divide the dough into 2 parts, one of which must be larger. Roll out the larger one into a sheet and put it in a greased pan to cover the bottom, sides and even spill out. Distribute the stuffing on top, cover with the second rolled out sheet and pinch the ends together, making something like a coronet.
Smear the pirogue with a little cream or oil if desired and put it to bake in a moderately heated oven until you get a nice brown color. The finished pie is brewed by covering with a towel.