1. Make 8 thin pancakes in a 20-cm/8-inch frying pan.
2. Place a slice of ham on each pancake and three asparagus spears on each piece of ham. Roll up pan-cakes to enclose filling. Place in a flameproof dish.
3. Melt butter over low heat in another pan. Remove pan from heat and stir in flour to 4 make a roux. Gradually stir in milk and cream, beat until smooth. Cook for 2 minutes.
5. Pour sauce over the pancakes and sprinkle with grated cheese.
6. Heat gently under a moderate grill for about 10 minutes or until cheese is bubbling.