Preheat the oven to 220°C (fan).

Add the flour and eggs to a large bowl and whisk until smooth. Pour in half the milk and whisk, then add the remaining milk, followed by the water, mustard and salt. Whisk until smooth.

Pour the batter into a jug and pop it in the fridge while you cook the sausages.

Add the sausages and olive oil to a metal roasting tin. Toss to coat, then roast for 15 minutes until starting to brown.

Carefully remove the hot tin from the oven and pour the batter around and between the sausages.

Return to the oven, reduce the temperature to 200°C (fan) and bake for 30 minutes until puffed up, crisp and golden. Avoid opening the oven door while it cooks.

Serve with some vegetables and plenty of gravy.