Here you go, Laura...
1 cup all-purpose flour
1 teaspoon salt
2 large eggs
1 cup whole milk
dash of malt vinegar
6 tablespoons of reserved beef fat from the roast
I usually do this in a well seasoned 8 inch cast iron skillet. You can also do it in muffin tins.
After you put the beef in to roast, mix the first five ingredients so you have a nice smooth batter. Cover and set aside on a cool area of the counter.
When the roast is done, remove it and crank up the heat to 425° (if it isn't already there...). Take the cast iron skillet and brush the inside with fat from the roast. Pour the 6 tablespoons of fat into the skillet and place it into the oven for 5 minutes to heat it up. Give the batter a stir in the meantime. When the fat in the pan is very hot, pour in the batter an get it back in the oven. Let it bake for 18 or 20 minutes or until puffed up and golden.