Add the oil and sausages into the 8-inch square tin.
Coat everything with the sunflower oil.
Place the 8-inch square tin into the oven and cook for ten minutes, to slightly brown sausages.
Whisk the flour and salt with the eggs in the mixing bowl until you have a smooth and thick paste.
Add a third of the milk into the mixing bowl, and whisk until smooth. Add the remainder of the milk and 50ml of water until the batter is completely smooth.
Remove the sausages from the oven and pour the batter around them. Return the sausages to the oven.
Reduce the oven temperature to 200c and cook for 30 minutes. DO NOT OPEN THE OVEN, until at least 25 minutes have passed (as your batter will sink).
Once crisp and golden, serve immediately with mashed potatoes and green vegetables.