Preheat the oven to 180C. Add a thin layer of oil to a casserole dish and pop in the oven to heat up.

While the oil heats, whisk the eggs and flour together then add enough milk to make a gloopy batter. Season with a little salt and pepper.

When the oil is smoking hot, add the onion slices and then the batter on top, then return to the oven for 20 - 25 mins until the pudding is puffed and browned.

While the Yorkshire bakes, fry the pork, mushrooms and thyme together over a medium heat until the pork is cooked through and the mushrooms tender.

As the pork finishes, make up the onion gravy as per the packet instructions and then whisk in the creme fraiche. Serve a slice of the Yorkshire pudding with the pork and mushroom mixture, with a helping of the creamed onion gravy.