Don't miss out on our special Christmas issue with free 2023 calendar - subscribe by 11 October!
To make the Yorkshire pudding, whisk the eggs with the flour until smooth, then gradually whisk in the milk. Season, then add the porcini powder, if using. The batter can be made up to a day ahead and chilled.
Heat the oven to 220C/200C fan/gas 8, and heat the oil in a 20cm ovenproof frying pan or skillet until very hot. Pour in the batter, transfer to the oven and cook for 20 mins until puffed up and golden. Reduce the oven to 180C/160C fan/gas 4, and cook for 5 mins more.
In the final 10 mins of the pudding’s cooking time, heat the butter in a second frying pan until foaming, then stir-fry the shallots, garlic and mushrooms for 3-4 mins until the mushrooms are golden. Splash in the sherry or wine, if using, and simmer for a minute. Remove from the heat, stir in the parsley and season. Set aside.
About 5 mins before the Yorkshire pudding is ready, make the poached eggs. Bring a small pan of water to the boil with the vinegar. Reduce the heat to a simmer, crack in the eggs and cook for 2-3 mins until just poached. Remove to a plate lined with kitchen paper using a slotted spoon, and drain. Spoon the mushrooms into the Yorkshire pudding, then carefully top with the poached eggs, season, sprinkle with the extra parsley and serve straight from the pan.