My mother made these when I was a boy in the 1930s.
Slice tomatoes ½-inch thick. Combine flour with salt and pepper and place in a shallow bowl. Meanwhile, heat oil in skillet over medium-high heat. Dip tomato slices in flour and place in hot skillet; brown thoroughly on both sides. When tomatoes are finished, add milk to contents of skillet and stir to make gravy. Pour gravy over tomatoes and serve as main dish or side dish.