Preheat the oven to 425 ℉ when you are ready to bake the dish.
Beat the eggs, then add the milk and water.
Add the flour and salt to a medium sized bowl, and make a well in the middle. Pour the egg mixture into the center.
Using a whisk or hand beater, start to incorporate the egg mixture into the flour. Beat well until there are no lumps and the mixture is smooth, then pour into a jug.
Rest for a minimum of 30 minutes. If resting for significantly longer (such as 4 hours or overnight,) cover and refrigerate, but remember to bring the mixture to room temperature before pouring into the pan.
If using a cast iron skillet, place it in the preheated oven with the lard or olive oil for 5 minutes. Remove from the oven, arrange the sausages (coating in the lard/oil) and put back into the oven for 5 minutes. (The cast iron skillet takes a bit longer to heat.) The key to good Yorkshire pudding is to make sure the pan and lard/oil is smoking hot.
If using a glass or oven-safe pan, arrange the sausages along with the lard, and put into the preheated oven.
After 5 minutes, take the pan, or cast iron skillet out of the oven, quickly whisk the Yorkshire pudding batter and pour over the sausages (be sure it's at room temperature.)
Place the pan or skillet back into the oven for about 35 minutes. While it's baking, prepare your choice of vegetable and have your mashed potatoes ready. Use lots of good quality butter (I love Lewis Road Creamery) and some milk and cream.
The toad in the hole is ready when the Yorkshire pudding is puffed and golden brown, and the sausages are also well-colored. The Yorkshire pudding won't deflate, but you do want to serve it hot.
You can pour the gravy directly onto the toad in the hole in the pan, or you can choose to cut and serve, and then offer gravy individually.