Clean and wash the leek and cut into thin rings. Cut the ham into strips. Heat oil in a pan. Fry the ham until crispy. Wash apples, quarter them, remove seeds and cut into thin slices.
Remove the ham from the pan. Steam leek and apples in the frying fat for 3-4 minutes. Leave to cool.
Line a quiche or springform pan (26 cm Ø) with baking paper. Unroll the dough and cut in half crosswise. Place the dough plates overlapping in the form, press up at the edges. Sprinkle the dough base with breadcrumbs.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2). Spread apples, leek and ham on the dough. Whisk sour cream and eggs. Season with a little salt and pepper. Pour into the mould.
Bake in the hot oven on the lowest shelf for 50-60 minutes. Cover if necessary. Serve quiche hot or cold.