My Mum is very English and we always had these with the Sunday Roast. She always had enough drippings but I sometimes don't. I add butter when I don't have enough drippings. She also used 1/2 water, 1/2 milk in her recipe.
Next month she'll be 92 and going strong. She'll be coming from London to stay 6 wks with me this December.
Mix flour, eggs, milk and salt in a large bowl, mixing until no bumps. Leave on counter while your roast cooks
Once your roast has cooked place 1/2 cup of drippings in an 8 by 13 pan...set it in a hot oven 450 degrees F, till it sizzles. This takes about 5 minutes but keep your eye on it. NOTE if you don't have 1/2 cup of drippings add the butter to the pan.
Once your drippings are sizzling hot, pour in the flour mixture to bake.
Put pan in the 450 degree oven, bake for 30 minutes
When done, the pudding will be puffy and golden brown. Cut in squares and arrange around the roast and serve.