Preheat your oven to 230C.In a muffin tray, add in a bit of oil to each tin.Place in the oven on the top shelf.In a mixing bowl, whisk together the flour, eggs, milk, and salt until it's a thin mixture.When the oil is bubbling hot, pull out of the oven (watch for the oil splattering), and pour the mixture evenly into each muffin tin.Place back in the oven for 20-30 minutes until the Yorkshire puddings have risen and are golden brown.