What you need:
First blend the flour and salt together, use a sifter if you have one. In a separate bowl beat the eggs and then add the milk. Using a whisk or electric mixer blend the eggs/milk mixture with the flour until the texture is consistent. Add the water and mix until smooth. Let it sit out for 20-30 minutes.
Meanwhile, preheat the oven to 425F. Add about a spoon full of olive oil to the bottom of each of the cups of the muffin tin. Put this in the oven until the oil is smoking. Warning: Don't let the oil burn.
Take out the the muffin tins and pour the batter into each cup filling about just over 1/2 way. Don't over fill the cups as the Yorkies will rise quite a bit. Place the tins back into the oven and bake for 20-23 minutes. Do not open the oven door during this time as it will cause the Yorkies to fall.
When they are done take them out and let cool for a bit.
The above picture is my second attempt at making Yorkies. I made the mistake of opening the oven the first time and while still tasty they didn't rise and were fairly dense. These go great with pretty much anything, but especially with roasts with gravy that can be sopped up using the Yorkie. Traditionally you are supposed to use the drippings from the roast in place of the oil, but as I didn't have any chunks of beef laying about to cook today I went with the oil.