This is savory (not sweet) English comfort food and we love it! It is part of dinner and goes great w/ meat and gravy. It's nearly identical in flavor and texture to a popover if you've ever had one.
The pud' rises high around the edges and the center remains more flat. It will sink rapidly as soon as you take it out of the oven, but it is impressive briefly! What is most common is to eat the pud' w/ beef gravy and roast beef. Most English people still eat Yorkshire pudding on most Sundays with roast beef. In England, you will often find a Yorkshire pudding filled with gravy and a couple of English sausages (bangers) laid in it. Sometimes they'll even stack chips (steak fries) on top of the bangers and gravy.
Growing up, I always ate it on Christmas eve when Grammy would make it with filet mignon. We make it every Christmas eve now to go with our beef. Grammy used a combo of beef drippings and butter to coat the pan and traditionally it is just beef drippings, but we find that using butter adds so much delicious flavor, so we recommend the butter. (Many English just use oil, but no great taste there!) Try it with real butter and not margarine. The butter is a key player in flavor.
You can make Toad in the Hole with Yorkshire pudding batter; another English fave of both adults and especially kids. In that, you make the batter as below but fry up some sausages and have ready so when you pour the batter into the pie pan you immediately put the cooked sausages around the pan (you can use cooked meatballs instead but it's not traditional) then proceed the same way, cooking for about 20-25 min at 425. The sausages are supposed to look like toads poking out of their hiding holes. David and I substituted turkey meatballs for the sausages and ate it w/ beef gravy and it was great. This is so easy to make! Toad in the Hole is a quick, tasty dinner the kids love and it's great on a budget. We just used a packet of beef gravy to make the gravy. (If you want cheapo turkey meatballs, buy ground turkey meat at Aldi. It's only 99 cents/lb.)
Yorkshire Pudding has been around in England for a while--it
is supposed that it was originally used to fill up dinner guests
cheaply so they would eat less of the meat since the pud' used to be
served as the first course. I can't believe that this isn't a common
dish in America. It's as comforting and great as mac-n-cheese and other
comfort foods, I think.
Using electric mixer (I use a simple small mixer that has the two small metal beaters attached,) mix together the flour, milk, salt and eggs until well blended and some bubbles form on surface. Let rest a half hour or longer. Place glass pie pan in cold oven and preheat oven to 425. When it's ready, put the butter in pan and put back in oven for it to melt briefly to coat bottom. Re-blend your batter again and very quickly take pie pan out of oven and pour batter into buttery pan and immediately place back in oven. Don't open oven door during baking. It will be done in 20-25 minutes. EASY!!