First crack the eggs into a jug & mark what the volume is. Then transfer eggs into a large mixing bowl.
Next, fill the jug up with the same volume of liquid - use 2 parts milk & 1 part cold water. Add this to the eggs.
Next measure out the same volume of flour & add to the eggs, milk & water.
Using a handheld electric mixer or a whisk, mix the batter until combined & smooth. Pass the batter through a sieve into a jug, cover with clingfilm & leave in the fridge overnight.
The next day, season the batter with a pinch of table salt & freshly cracked black pepper. Whisk to combine & leave at room temperature for at least an hour. If the batter is a bit thick, thin it out with a splash of water (the batter should have the consistency of double cream).
Preheat an oven to 220°c.
Place a tablespoon of oil into each hole of the muffin tin & place into the oven to heat up for at least 30 minutes.
Once the oil is hot, carefully remove the tin from the oven & fill each hole 2 thirds of the way up with batter. Cook the puddings for 25-30 minutes, until well risen & a deep golden brown.