for 12 small puddings:
Mix together. Preheat oven to 220 degrees celsius. Put half a tsp of oil (or better goose fat) into each of the pudding holes of your form. Put it into the oven until the oil is fuming.
Quickly take out, pour even amounts of batter into each hole (almost to the top), and quickly put back into the oven. Speed is of the essence here as you don't want the oil to get too cold.
After 10 to 15 minutes, your Yorkshire Puddings are done!