Pare and scoop out the seeds of a moderate sized cucumber. Grate one tablespoonful of cheese, one of bread-crumbs, a little chopped parsley, chives, pepper, salt, butter. Stuff cucumber and bake in the oven for half an hour. Have sauce made thus: one tablespoonful of cheese, teaspoonful flour, teaspoonful butter, half a teaspoonful of mustard, little pepper and salt. Stir in the saucepan with a tablespoonful of milk; stir till thick. Pour this over cucumber, cover with bread-crumbs brown, and serve.