The key is getting the batter right; not enough flour, and you end up with sausage omelette. Too much, and you've got a stodgy mess.
I have experimented and have come up with my ideal recipe. It makes enough for two, if you're not planning on having spuds with it. If you fancy mash or roasties, then there should be enough for four people. Just add more sausages. I prefer it without spuds, serving it with veg and decent onion gravy.
One final comment; it's not a dish for the faint hearted. The fat from the sausages, if you're not going veggie, adds to the taste of the batter, and you will need a fair amount of oil in the dish in any case. I like my Yorkie pudding to be crispy on on the outside, and moist in the middle. Not uncooked, mind. The crispiness comes from the oil. Add less, and you will have a perfectly fine Yorkie, just not a crispy one.
For the batter:
½ cup of flour
1 cup of milk
Salt and pepper
Sausages - 2-3 per person
Vegetable or sunflower oil
Add the ingredients to a bowl
Leave to rest
Preheat the oven to about 220°C
At this stage, I add a couple of ice cubes - I don't know why this works, it does
Pour the oil into a non-stick dish - I tend to make sure that there is a 2-3mm coating on the bottom. Also bear in mind that if you are using meat sausages, these will release oil, and add to what you have
Cook the sausages for about 10 minutes
After the 10 minutes is up, take the dish out of the oven, quickly turn the sausages and then add the batter - the batter needs to be added whilst the oil is very hot, so be careful when doing this
Return to the oven, and turn the temp down to 200°C
Cook for 25 minutes
There you have it, perfect comfort food!