Overnight Scrambled Egg and Ham Casserole with Cheese Sauce

Scrambled Egg Casserole from Mrs Mapp
This Scrambled Egg Casserole by Mrs. Mapp is a cherished breakfast classic that blends creamy scrambled eggs with ham, mushrooms, and a rich homemade cheese sauce. Layered with buttery breadcrumbs and baked to golden perfection, it’s the kind of comforting dish that turns any morning into a family gathering. The recipe captures the essence of hearty American casseroles from mid-century kitchens, simple, filling, and designed for sharing. Whether served at brunch, a church potluck, or a cozy weekend breakfast, this casserole brings together savory flavors and nostalgic warmth in every bite.
Prep Time 25 minutes
Cook Time 30 minutes
Chill Time 8 hours
Total Time 8 hours 55 minutes
Course Breakfast
Cuisine American
Servings 8
Calories 380 kcal

Ingredients
  

Main Casserole:

  • 1 cup ham (cubed )
  • 3 tbsp butter (or margarine, melted)
  • ¼ cup green onion (chopped )
  • 12 eggs
  • 4 oz mushrooms (drained)
  • ¼ cup Oleo (melted, for breadcrumbs)
  • 2 ½ cups soft breadcrumbs
  • tsp paprika

Cheese Sauce:

  • 2 tbsp butter
  • 2 ½ tbsp plain flour
  • 2 cups milk
  • ½ tsp salt
  • tsp pepper
  • 1 cup cheese (shredded, cheddar recommended)

Instructions
 

Step 1: Prepare the Base

  • Sauté cubed ham and chopped green onion in 3 tbsp melted oleo over medium heat.

Step 2: Scramble the Eggs

  • Add the eggs to the pan and cook over medium heat until set.

Step 3: Add Mushrooms and Cheese Sauce

  • Stir in the drained mushrooms and prepared cheese sauce.

Step 4: Prepare the Pan

  • Grease a 13x9x2-inch pan. Combine ¼ cup melted oleo with 2½ cups soft breadcrumbs. Spread half the crumbs in the bottom of the pan.

Step 5: Assemble the Casserole

  • Pour the egg mixture over the breadcrumb base. Top with remaining crumbs and sprinkle lightly with paprika.

Step 6: Chill Overnight

  • Cover and refrigerate overnight to allow flavors to meld.

Step 7: Bake

  • Uncover and bake at 350°F (175°C) for 30 minutes or until bubbly and golden brown.

Step 8: Make the Cheese Sauce

  • Melt butter in a heavy saucepan over low heat. Blend in flour and cook 1 minute. Gradually add milk, cooking and stirring over medium heat until thickened. Add salt, pepper, and cheese. Stir until smooth.

Tips

  • Use breakfast sausage or bacon instead of ham for a different flavor.
  • Substitute sautéed bell peppers or spinach for mushrooms if preferred.
  • For a milder onion flavor, sauté the green onions longer or reduce the amount.
  • Add shredded cheddar, Colby Jack, or Swiss directly to the egg mixture for extra cheesiness.
  • Use fresh mushrooms instead of canned; just sauté before adding.
  • For a lighter version, use half-and-half milk substitute or reduced-fat cheese.
  • Assemble up to 24 hours ahead for easy holiday or brunch hosting.
  • Try topping with buttered cornflakes or crushed crackers instead of breadcrumbs.
  • Serve with fruit salad, toast, or breakfast potatoes for a complete meal.

Nutrition

Calories: 380kcalCarbohydrates: 12gProtein: 22gFat: 27gSaturated Fat: 13gPolyunsaturated Fat: 2gMonounsaturated Fat: 8gTrans Fat: 0.5gCholesterol: 340mgSodium: 750mgPotassium: 350mgFiber: 1gSugar: 5gVitamin A: 800IUVitamin C: 2mgCalcium: 220mgIron: 2mg
Keyword breakfast casserole, brunch, cheese sauce, comfort food, eggs, family favorite, Ham, make-ahead, vintage recipe
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