Place 1 slice of bread on a plate. Top the bread with ½ cup of mashed potatoes. Layer 2 ounces of leftover pot roast over the mashed potatoes, then top with 1 ounce of gravy. Serve while warm.
4 slices bread
Notes
The calories listed are an approximation based on the ingredients and a serving size of 1 finished open-faced pot roast sandwich with gravy. Actual calories will vary.