Ham and cheese roulade

1. Melt the butter in a medium saucepan. Add the flour and stir for 1 minute. Add the milk gradually, stirring constantly. Cook for about 5 minutes until mixture thickens. Remove from heat and stir in pepper and mustard.
2. Beat the egg yolks in a small bowl. Beat in a little of the white sauce mixture. Stir the egg yolk mixture into the remaining white sauce and set aside.
3. Beat egg whites until stiff, but not dry. Fold the white sauce into the beaten egg whites.
4. Pour mixture into a lined and greased swiss roll tin and bake in a preheated oven at 200 ºC for 20 to 25 minutes until firm on top.
5. Cover the roulade with foil, invert it and peel off the lining paper.
6. Sprinkle the grated cheese evenly over the surface, followed by a layer of spinach leaves and then a layer of sliced ham.
7. Carefully roll up the roulade, using the foil to help lift as you roll. Place on an ovenproof platter and return to the oven for about 5 minutes until heated through. Slice and serve with a salad.