Wash the green beans and remove the ends and threads.
Then pour into a large saucepan with water - the water should be 2 fingers wide above the beans - and add a level teaspoon each of salt, pepper and savory. Simmer for 15-20 minutes. Then cool the beans in ice water, saving the stock.
Thaw the puff pastry and cover each sheet with a slice of ham. Spread a sixth of the beans on each and roll up the puff pastry. Moisten the sides and ends with water and press down.
Place on a baking sheet lined with baking paper and bake for 15-20 minutes.
Prepare a light sauce from 6 teaspoons of margarine, 5 tablespoons of flour, 250 ml of bean stock and some instant vegetable stock and use it to serve the green beans in your dressing gown.