Leftover Roast Beef Casserole

leftover roast beef casserole
Diana Rattray
  • Total: 45 mins
  • Prep: 15 mins
  • Cook: 30 mins
  • Yield: 4 servings
Ratings (22)

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. 

Even if you don't have leftover roast beef, you can 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.

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

What You'll Need

  • 1 (10-ounce) package frozen peas and carrots (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

How to Make It

Preheat the oven to 350 F.

Lightly grease a 1 1/2-quart to 2-quart casserole or spray it with nonstick cooking spray.

Put the peas and carrots in a medium saucepan; add the frozen pearl onions and cover with water. Bring to a boil. Reduce the heat and cook for about 5 minutes, or until the vegetables are tender. Drain thoroughly and transfer the vegetables to a large bowl.

Combine the beef with the gravy and then add it to the bowl with the onions and vegetables.

Mix well.

Transfer the beef and vegetable mixture to the prepared casserole and top with shredded cheddar cheese.

Bake in the preheated oven for  25 to 35 minutes, or until the filling is bubbling and the cheese has melted.


  • 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.

Expert Tips

  • 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.


Nutritional Guidelines (per serving)
374 Calories
16g Fat
43g Carbs
15g Protein
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)