Looking for a breakfast dish that feels as indulgent as Sunday brunch but as effortless as a weekday morning? Enter this Ham and Cheese Make-Ahead Breakfast Casseroleβ€”a sophisticated twist on the classic egg-and-sausage bake. Inspired by The Kitchn, this recipe takes familiar comfort food and elevates it with rich GruyΓ¨re cheese, savory pancetta, and aromatic thyme. Whether you’re hosting a holiday breakfast or simply planning ahead for a busy week, this dish combines the best of convenience and flavor.

The magic lies in its layers: pillowy challah bread soaks up a spiced egg custard, while golden caramelized onions and crispy pancetta bring savory depth to every bite. Topped with fresh Roma tomatoes for a burst of brightness, this casserole is hearty yet refined. Best of all? You can assemble it the night before, letting the flavors meld beautifully while you sleep. When morning arrives, just pop it in the oven and enjoy a warm, bubbling masterpiece guaranteed to impress your family and guests.

Make-ahead ham and cheese Christmas morning breakfast casserolePin
Using ham, cheese, and eggs, this make-ahead breakfast casserole is full of flavor. Image: Liza Graves

 

Ham and Cheese Casserole Breakfast Make AheadPin

Ham & Cheese Make-Ahead Breakfast Casserole

Liza Graves (adapted from The Kitchn)
You can't go wrong serving this ham and cheese breakfast casserole on Christmas morning!
5 from 4 votes
Prep Time 8 hours
Cook Time 45 minutes
Total Time 45 minutes
Course Breakfast
Cuisine American
Servings 8 servings
Calories 825 kcal

Ingredients
  

  • 6 cups loosely packed day-old challah or other egg-enriched bread broken into pieces
  • 2 tbsp olive oil
  • 1 medium yellow onion thinly sliced into strips
  • 1Β½ tsp kosher salt divided
  • ΒΌ tsp granulated sugar
  • 8 oz thickly sliced pancetta diced
  • 10 large eggs
  • 2 cups whole milk
  • 1 tsp dry mustard
  • Β½ tsp ground nutmeg
  • Β½ tsp garlic powder (We prefer the Private Selection brand "California Roasted Garlic Powder" found in the dried spice section at Kroger.)
  • 3 tsp dried or fresh thyme leaves
  • 1 tsp freshly ground black pepper
  • 1 cup grated GruyΓ¨re cheese about 4 ounces of good quality Swiss cheese
  • 2 Roma tomatoes sliced

Instructions
 

  • Heat 2 tablespoons of olive oil in a skillet over medium heat until shimmering. Add the onions, Β½ teaspoon of the salt, and sugar. Cook until lightly caramelized (a golden-brown color), about 15 minutes β€” stir occasionally so as not to burn.
  • In another skillet, sautΓ© the pancetta until it begins to crisp, about 8-10 minutes. Place on a paper towel to drain.
  • Whisk the eggs, milk, dry mustard, nutmeg, garlic, thyme, remaining teaspoon of salt, and pepper together in a large bowl.
  • Grease a 9x13 baking dish and spread the cubed bread along the bottom.
  • Place the pancetta over the bread cubes, then place the caramelized onions on top. Next, sprinkle on the cheese, and then pour the egg mixture over everything. Make sure all the bread cubes are soaked a bit with the egg mixture.
  • Lastly, place the sliced tomatoes across the top.
  • Cover with aluminum foil and refrigerate overnight.
  • While oven preheats to 350 degrees Fahrenheit, take the casserole out of the refrigerator to warm up a bit on the counter (maybe 15 minutes).
  • Bake until the edges are bubbling, 40-50 minutes. Check the middle with a knife; if it comes out clean, the casserole is ready.

Nutrition

Calories: 825kcalCarbohydrates: 94gProtein: 36gFat: 34gSaturated Fat: 12gPolyunsaturated Fat: 7gMonounsaturated Fat: 13gTrans Fat: 1gCholesterol: 248mgSodium: 1706mgPotassium: 618mgFiber: 8gSugar: 15gVitamin A: 733IUVitamin C: 5mgCalcium: 523mgIron: 8mg
Keyword christmas, Holiday meal, Breakfast casserole, Holiday recipe
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Liza Graves
About the Author
Liza Graves

As CEO of StyleBlueprint, Liza also regularly writes for SB. Most of her writing is now found in the recipe archives as cooking is her stress relief!