Wash and peel the potatoes and cut them into thin slices. Pears wash, quarter and remove the core. Cut the pear quarters into slices. Layer potatoes and pears fan-shaped in a greased gratin dish.
Cut Roquefort into cubes. Mix milk, 100 g Roquefort, egg yolk and starch with the whisks of the hand mixer. Season with a little salt, pepper and nutmeg and pour over potatoes and pears.
Sprinkle with remaining cheese and bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for approx. 45 minutes. Cut the bacon slices in half, place them on the gratin after approx. 25 minutes and bake with them.
Serve garnished with parsley.