If you have leftover prime rib, this easy breakfast sandwich is an excellent way to put it to delicious use. It comes together quickly, tastes fantastic, and might convince you to roast a larger cut next time just so you have plenty of leftovers to play with.
Leftover Prime Rib Breakfast Sandwich
I love making prime rib and intentionally cook a big roast so there are plenty of leftovers to transform into other meals. This sandwich highlights tender slices of prime rib tucked into a toasted croissant with cheesy scrambled eggs and a tangy horseradish mayo. It’s simple, satisfying, and perfect for a special weekend breakfast or a make-ahead weekday option.
Why You’ll Love This Recipe
- Quick prep: Minimal steps—slice, sauté, scramble eggs, and assemble.
- Family-friendly: A hearty sandwich that appeals to kids and adults alike.
- Great for meal prep: Make several, wrap in foil, and reheat in an air fryer or oven for an easy takeaway breakfast.
Try a prime rib French dip or other leftover-focused recipes for more ideas.
Recipe Shopping List
Most of these items may already be in your kitchen if you cooked the roast yourself. For precise amounts, refer to the ingredients list below. This sandwich uses simple, familiar ingredients and accommodates swaps—use bagels or English muffins in place of croissants, or choose your favorite cheese.
- Prime rib: Leftover roast, sliced thin or cut into bite-sized pieces. Using the rarer slices helps avoid overcooking when reheating.
- Butter: For sautéing the meat and cooking the eggs.
- Eggs: Fresh eggs make a big difference in texture and flavor.
- Milk: A splash in the eggs keeps them tender—whole milk or 2% works best.
- Seasoning: Salt, pepper, garlic, or a preferred steak seasoning.
- Croissants: Fresh or store-bought; other rolls or English muffins work too.
- Shredded cheddar cheese: Sharp cheddar complements the beef, but use what you like.
- Mayonnaise, horseradish, Dijon mustard: Combined into a bright, tangy spread for the croissant.
How To Make This Recipe
Below is a concise overview of the steps. Read the full instructions before you start so everything moves smoothly at the stove.
- Prep: Thinly slice leftover prime rib and season lightly. Whisk eggs with milk, salt, and pepper until smooth. Split and lightly toast croissants in a 350°F oven until warm and golden. Combine mayo, horseradish, and Dijon in a small bowl. Shred cheese if needed.
- Sauté the prime rib: Heat a skillet with 2 tablespoons butter over medium heat. Add the slices in a single layer and let them warm and develop a touch of color for 30–60 seconds per side. Remove to a plate and tent with foil to keep warm.
- Cook the eggs: Reduce heat to medium-low, add 1 tablespoon butter, and pour in the egg mixture. Stir gently, forming soft curds. When eggs are almost done but still a little glossy, fold in the cheese and cover the pan for 30–60 seconds to melt the cheese and finish the eggs off the heat.
- Assemble: Spread the horseradish mayo on the croissant halves, layer on the warm prime rib, then top with the cheesy scrambled eggs. Close the sandwich and serve immediately while the croissant is crisp and the filling is hot.
Ingredients (Yield: 4 sandwiches)
- 1 pound sliced prime rib
- 4 tablespoons butter
- 8 eggs
- ¼ cup milk
- 1 teaspoon steak seasoning or salt and pepper
- 4 croissants
- 1 cup shredded cheddar cheese
- ⅓ cup mayonnaise
- 1½ teaspoons Dijon mustard
- 1 teaspoon prepared horseradish (adjust to taste)
Instructions
- Season the sliced prime rib and whisk the eggs with milk, salt, and pepper until slightly frothy.
- Toast croissant halves in a 350°F oven for 4–6 minutes until warm and lightly crisp.
- In a skillet over medium heat, melt 2 tablespoons butter and briefly sauté the prime rib until warmed through and slightly browned. Remove and keep warm.
- Add 1 tablespoon butter, reduce heat to medium-low, and gently scramble the eggs, keeping them soft. When nearly cooked, stir in the shredded cheese and cover for 30–60 seconds to melt.
- Mix mayo, Dijon, and horseradish to taste. Spread on the croissant cut sides, layer prime rib and cheesy eggs, then close and serve immediately.
Tips: Use thin slices of prime rib so they heat quickly without overcooking. Adjust the horseradish in the mayo to control the spice level. For a fresh peppery note, add a few arugula leaves before closing the sandwich.
Nutrition (approximate per serving)
- Calories: 1331
- Total Fat: 103 g (Saturated Fat: 45 g)
- Cholesterol: 614 mg
- Sodium: 1219 mg
- Carbohydrates: 35 g (Fiber: 2 g, Sugar: 8 g)
- Protein: 59 g
Nutrition estimates are approximate. If you require precise values for dietary or medical reasons, consult a trusted nutrition resource.
More Easy Breakfast Recipes
- Traeger Egg Bake
- Ham and Cheese Tortilla Quiche
- French Toast
- Homemade Dry Pancake Mix
Enjoy this leftover prime rib breakfast sandwich—hearty, savory, and the perfect way to start the day.