Prick the sausages and fry very quickly in a hot frying pan just to brown the outside (3 minutes maximum).
Sift the flour and salt through a sieve (strainer) into a mixing bowl and make an indent in the centre. Break the egg into the indent and stir in half of the milk, gradually working the flour down from the sides. Beat this mixture vigorously until it is smooth and bubbly, then stir in the remainder of the milk.
In a metal baking tray about 2" (5cm) deep by 8" (20cm) square, place a large knob of beef dripping (or duck or goose fat) and place into a preheated hot oven (Mk 7 - 425ºF - 220ºC) until the fat has melted and is smoking hot. Place the sausages side-by-side (but not touching) then pour the batter over the top until the tin is half full (any surplus batter can be cooked in a separate tin). Bake for at least 20-25 minutes depending on the depth of the tin. The pudding will rise high above the top of the tin and will be nicely browned around the edges and golden in the middle. Delicious just with Creamed Potatoes.