Place the glass dishes in the oven and preheat to 220°C (200°C fan).
Once the oven is at temperature add the beef dripping or oil and place the sausages in the dish(es). For frozen sausages, cook for 15 minutes.
Meanwhile, prepare the batter. Measure out the flour, salt, and pepper in a large bowl.
In another bowl whisk together the eggs and milk. Gradually add the wet mixture to the dry ingredients, whisking until smooth.
Carefully remove the hot dish from the oven and pour the batter over the sausages.
Return the dish to the oven and bake for 25-30 minutes, or until the batter is puffed and golden. Do not open the oven during this time or the batter will deflate.