Pot roast sandwich on a plate

Pot Roast Sandwiches

  • Author: RebeccaBlackwell
  • Total Time: 15 minutes
  • Yield: 4 open face sandwiches


Pot Roast Sandwiches are a delicious way to use up leftover pot roast and get dinner on the table in about 15 minutes.


  • 4 thick slices of French bread, Italian bread, or sourdough
  • 3/4 cup mayonnaise
  • 1 tsp minced garlic
  • 1/3 cup fresh parsley, chopped fine
  • 1/3 cup fresh cilantro, chopped fine
  • 3/4 cup stewed onions, reserved from crock pot French onion soup – OR 1 large yellow onion
  • 1620 oz leftover pot roast – OR 1 lb deli roast beef
  • 8 oz gruyere cheese, sliced very thin
  • 4 cups dark leafy greens, like spinach or kale


  1. Preheat your oven’s broiler.
  2. Toast the slices of bread and lay them side by side on a baking sheet.
  3. Stir the garlic, parsley, and cilantro into the mayonnaise. Spread a generous layer of the herbed mayonnaise over each slice of toasted bread.
  4. If you have stewed onions, divide them amongst the sandwiches, layering the onions over the mayonnaise. If you don’t have stewed onions on hand, peel 1 large yellow onion and slice it into thin slices, about 1/4 inch thick. Heat 1 tbsp of olive oil in a frying pan over medium heat. Sautéed the onions in the oil until they are soft and beginning to brown. Distribute over the sandwiches.
  5. Layer the pot roast or roast beef over the onions on each sandwich and top with a few slices of cheese.
  6. Place the sheet of sandwiches under the broiler to melt the cheese. Watch carefully – the cheese will go from just starting to brown to burnt very quickly.
  7. Remove the sandwiches from the oven, distribute among 4 plates, and top each with a generous portion of kale, spinach, or other dark leafy greens.