Cook bacon in a skillet, use medium heat and turn frequently. When slices are evenly cooked, remove from the skillet and place on a paper towel to drain. Cover with another towel lightly and place in the oven set on warm.
Pour off excess fat from the skillet, leaving just enough to cover the bottom of the skillet to a depth of 1/8 inch. Mix together flour, salt and pepper and coat slices of the liver with this mixture. Cook liver in drippings over medium heat. As soon as the liver is a delicate brown on each side, it is done. Remove the liver from the skillet and keep warm with the bacon and then quickly fry thick slices of onions in the drippings.