Peel the potato, cut into slices and boil in salted water. Wash and halve the tomatoes, drain the asparagus and cut into 2 cm long pieces. Mix the egg with the whipped cream and season with salt, pepper and nutmeg. Strain the firm potatoes. Mix everything and pour into an ovenproof dish. Sprinkle with cheese and bake at 200 ° C top / bottom heat for about 30 minutes.