1/2 pint of milk and water, 1 egg, 1 teaspoonful of cornflour, a pinch of saffron, pepper and salt to taste. Boil the milk and water with the saffron, and see that the latter dissolves thoroughly. Add seasoning, and thicken with the cornflour; beat up the egg, and after having allowed the Sauce to cool a little, add it gradually, taking care not to curdle the Sauce. Heat it up, but do not let it boil. To easily dissolve the saffron, it should be dried in the oven and then powdered.
The Allinson Vegetarian Cookery Book, by Thomas R. Allinson (Year 1915)