Leftover Beef and Potato Casserole
Give your leftover roast beef a delicious makeover with this hearty casserole. Made with mashed potatoes, gravy, steamed peas, and cheddar cheese, it’s a meal you won’t want to miss.
Leftover roast beef, mashed potatoes, and gravy make a delicious meal with the addition of steamed peas and some cheddar cheese. It’s an excellent way to repurpose a roast beef dinner. You might want to plan a larger roast and extra mashed potatoes so you can enjoy this casserole. I use a jar of beef gravy when I don’t have enough leftover gravy, but you8 could also make gravy from a dry mix.
Feel free to make the casserole with leftover roast pork or lamb instead of beef, and use whatever vegetables you like or have on hand. I like peas or peas and carrots.
What You’ll Like About This Dish
Perfect use for leftovers. A smart way to turn extra roast beef and mashed potatoes into a new, satisfying meal.
Hearty and comforting. With rich gravy, tender beef, and creamy potatoes, this is the ultimate comfort casserole.
Customizable and flexible. Swap the beef for pork or lamb, use other veggies, or add more cheese to suit your taste.
Ingredient Notes
- Roast Beef: Slices of leftover roast beef, pot roast, pork roast, or even meatloaf work well.
- Mashed Potatoes: Use seasoned mashed potatoes. If cold, let them soften slightly for easier spreading.
- Onions: Sliced and browned with butter and a pinch of sugar for sweet flavor.
- Gravy: Use leftover homemade gravy or a can of store-bought beef gravy (about 10.5 oz).
- Peas: Thawed frozen peas add a pop of color and flavor—sub with mixed vegetables if preferred.
- Cheddar Cheese: Just a bit on top for flavor and melt factor—mild or sharp, your choice.
Steps to Make Leftover Beef and Potato Casserole
- Preheat your oven to 375°F and grease a 2-quart baking dish.
- In a skillet, melt butter and cook sliced onions with sugar until golden and tender.
- Spread half of the mashed potatoes in the bottom of the dish.
- Layer the sliced meat, caramelized onions, peas, and gravy over the potatoes.
- Spread the remaining mashed potatoes over the top.
- Bake uncovered for 30 minutes, until hot and bubbly.
- Sprinkle cheese on top and bake for 5 to 10 more minutes, or until melted and lightly browned.
Tips
- Shortcut gravy: A jar of beef gravy works great if you don’t have leftovers.
- Even layer: Spread potatoes as evenly as possible for a smooth top and good coverage.
- Add more vegetables: Peas and carrots, corn, or green beans all work well.
Recipe Variations
- Use pork or lamb. Leftover roast pork or lamb makes an equally tasty casserole.
- Swap the vegetables. Try corn, green beans, or mixed vegetables instead of peas.
- Add herbs or spices. Stir some thyme, rosemary, or garlic powder into the mashed potatoes.
- Make it cheesier. Mix some shredded cheese into the potatoes as well as on top.
Serving Suggestions
- Serve with a simple side salad for contrast and crunch.
- Add cranberry sauce or chutney for a sweet counterpoint.
- Pair with dinner rolls or crusty bread to round out the meal.
How to Store and Reheat
Refrigerate: Store leftover casserole in an airtight container for up to 4 days.
Freeze? This casserole can be frozen for up to 2 months. Thaw overnight in the refrigerator before reheating.
To Reheat: Cover and bake at 350°F until heated through, or microwave individual portions until warm.
Leftover Beef and Potato Casserole
Ingredients
- 1 tablespoon butter
- 2 cups onions, sliced
- 1 teaspoon sugar
- 3 cups mashed potatoes, seasoned
- 8 slices roast beef, pot roast pork roast, or meatloaf
- 1 cup peas, frozen, thawed
- 2 cups beef gravy, about 10 1/2 ounces, or 1 cup leftover gravy
- 1/4 cup cheddar cheese, shredded mild
Instructions
- Heat the oven to 375°F and grease a 2-quart baking dish.
- Heat the butter in a large nonstick skillet over medium heat. Add the onions, sprinkle with sugar, and cook until they begin to brown. Continue to cook, stirring, for 7 minutes, until tender.
- Spread half of the mashed potatoes in the baking dish. layer with the meat, onions, peas, and gravy, in that order. Top with the remaining mashed potatoes.
- Bake the casserole for 30 minutes.
- Sprinkle shredded cheese over the potato topping and return the casserole to the oven for 5 to 10 minutes, until the topping is lightly browned and the cheese is melted.
Nutrition
Disclaimer:
Our nutritional information is based on a third-party application that analyzes the ingredients list to determine the values. The information is meant to be helpful, but should be considered an estimate. Values may differ depending on measurements, brands, serving variations, and database availability.
