||Prepare the gravy – finely slice your onions (either red or white are fine). In a heavy-based saucepan, heat the oil on a low heat and add the onions and salt. Once the onions are softened and translucent add the sugar and increase the heat, keep the onions moving until a deep caramelized brown is achieved. Add the balsamic vinegar, Worcestershire sauce and thyme, reduce the liquor by half and add to the pre-made gravy.
||Prepare the batter – place the flour in a mixing bowl and make a small well in the centre, pour in the beaten eggs and a small amount of the milk. Stir, gradually bringing the flour into the centre and adding the remainder of the milk until you have a smooth batter. Set aside for 30 minutes to rest while you prepare the sausages.
||Preheat the oven to 200°C, 400°F, Gas Mark 6.
||Add the olive oil and sausages to an oven tray and cook in the oven for approx. 10-15 minutes until brown on all sides.
||Remove the tray from the oven and pour over the batter; return to the oven and cook for 30-40 minutes until the batter is well-risen and golden.
||Serve with peas and the caramelised onion gravy.