Leftover Roast Beef Casserole

Leftover Roast Beef Casserole Recipe

The Spruce 

  • Total: 45 mins
  • Prep: 15 mins
  • Cook: 30 mins
  • Yield: 4 servings
Nutritional Guidelines (per serving)
374 Calories
16g Fat
43g Carbs
15g Protein
See Full Nutritional Guidelines Hide Full Nutritional Guidelines
Nutrition Facts
Servings: 4 servings
Amount per serving
Calories 374
% Daily Value*
Total Fat 16g 21%
Saturated Fat 9g 43%
Cholesterol 42mg 14%
Sodium 2423mg 105%
Total Carbohydrate 43g 16%
Dietary Fiber 5g 19%
Protein 15g
Calcium 313mg 24%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

This leftover roast beef casserole is a great way to enjoy leftover roast beef. It's simply a mixture of cooked roast beef, gravy, and vegetables. A cheese topping completes the layers. 


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It's a great spur-of-the-moment dish to fix and serve with boiled or mashed potatoes. It's also excellent over rice or noodles as well.


  • 1 (10-ounce) package peas and carrots (frozen, about 1 1/2 cups)
  • 1 cup pearl onions (frozen)
  • 2 cups diced leftover roast beef (1/4-inch to 1/2-inch dice)
  • 1 cup beef gravy (canned or made from dry mix, or see homemade, below)
  • 1/2 cup shredded sharp cheddar cheese

Steps to Make It

  1. Gather the ingredients.

    Leftover Roast Beef Casserole Recipe
    The Spruce 
  2. Preheat the oven to 350 F. Lightly grease a 1 1/2-quart to 2-quart casserole or spray it with nonstick cooking spray.

    Leftover Roast Beef Casserole Recipe
    The Spruce
  3. Put the peas and carrots and frozen pearl onions in a medium saucepan, cover with water, and bring to a boil.

    Leftover Roast Beef Casserole Recipe
    The Spruce
  4. Reduce the heat and cook for about 5 minutes, or until the vegetables are tender.

    Leftover Roast Beef Casserole Recipe
    The Spruce
  5. Drain thoroughly and transfer the vegetables to a large bowl.

    Leftover Roast Beef Casserole Recipe
    The Spruce
  6. Combine the roast beef with the gravy and then add it to the bowl with the onions and vegetables. Mix well.

    Leftover Roast Beef Casserole Recipe
    The Spruce 
  7. Transfer the beef and vegetable mixture to the prepared casserole and top with shredded cheddar cheese.

    Leftover Roast Beef Casserole Recipe
    The Spruce
  8. Bake in the preheated oven for 25 to 35 minutes, or until the filling is bubbling and the cheese has melted.

    Leftover Roast Beef Casserole Recipe
    The Spruce
  9. Serve and enjoy!

    Leftover Roast Beef Casserole Recipe
    The Spruce


  • There are many ways to use leftover roast beef. Make a cottage pie with leftover roast beef, use it in sandwiches, make open-faced sandwiches with purchased or leftover gravy, or heat it in your favorite stroganoff sauce. Or slice the beef into strips and add it to a tossed salad.
  • If you don't have a gravy mix or canned gravy, make quick and easy beef gravy. Melt 3 tablespoons of butter in a saucepan over medium heat. Add 3 tablespoons of flour and cook for 2 to 3 minutes, stirring constantly. Add 1 1/2 cups of beef stock and salt and pepper, to taste. Cook until thickened, stirring constantly. For a darker gravy, add about 1/2 teaspoon of gravy browning sauce, such as Kitchen Bouquet or Gravy Master.

Recipe Variations

  • Cottage Pie: If you have mashed potatoes—leftover or purchased—warm them and spread them over the beef and vegetable mixture before topping the casserole with cheese. Top the potato layer with the cheese and bake as directed, or until the potatoes are lightly browned.
  • Even if you don't have leftover roast beef, you can still make this easy dish. Use thick-sliced deli roast beef or use diced raw meat. Stir-fry the raw beef before combining it with the gravy.
  • Or use browned ground beef in the recipe.
  • Diced leftover lamb or roast pork are some other excellent alternatives. Use beef or pork gravy with the diced meat.
  • The vegetables are versatile as well. Instead of peas and carrots, use frozen mixed vegetables, peas, green beans, or diced carrots. If you don't have pearl onions, use 1 medium onion, halved and sliced.