Yorkshire Pudding Mix
Use this recipe and you can't go wrong.
If you want to get the best results with Yorkshire puddings, you need to invest in some decent Yorkshire pudding tins, you can use muffin tins but they can be a bit of a horror to clean afterwords.
When greasing the tins, I find lard is better than oil. you'll know when the lard is hot enough when you can see it slightly smoking.