The Only Make-Ahead Breakfast Casserole You’ll Need for Your Holiday Crowd

A diner breakfast upgrade that’s perfect for a filling meal any time of day.

By
Jasmine Smith
Jasmine Smith
Jasmine Smith is a recipe developer and tester for the Dotdash Meredith Food Studios in Birmingham, Alabama, and her work has been published in Southern Living, EatingWell, RealSimple, Food & Wine Magazine, MyRecipes, Health, and Simply Recipes. 
Learn about Simply Recipes' Editorial Process
and
Sara Bir
Sara Bir
Sara is a chef, culinary educator, and author of three cookbooks, The Pocket Pawpaw Cookbook, Tasting Ohio and The Fruit Forager's Companion. The latter won a 2019 IACP Cookbook Award.
Learn about Simply Recipes' Editorial Process
Published December 30, 2023
Slice of Denver omelette hashbrown casserole lifted from a casserole dish

Simply Recipes / Photo by Fred Hardy / Food Styling by Jennifer Wendorf / Prop Styling by Lindsey Lower

The sight of a Denver omelet freshly slid from a hot skillet to a big plate is a glorious thing indeed. Those cubes of ham, shreds of cheese, and bits of bell pepper are a calling card for satisfaction. You know you have a fine meal in store, preferably with toast, hashbrowns, and a big cup of coffee at the ready.

This Denver omelet hashbrown casserole is perfect for anyone who doesn’t want to labor at a home omelet station when guests are around. All the standard ingredients go into a baking dish bulked up with handy frozen hash browns.

You can assemble it ahead of time or throw it together right before serving. It’s a great way to use up some leftover ham, so bust it out for a special breakfast the day after a big holiday meal–or make it on a weeknight since it’s easy and so, so satisfying.

Slice of Denver omelette hashbrown casserole lifted from a casserole dish, and in the surroundings, a stack of plates and a mug

Simply Recipes / Photo by Fred Hardy / Food Styling by Jennifer Wendorf / Prop Styling by Lindsey Lower

All the Egg-y Casseroles

Denver Omelette Hashbrown Casserole

Prep Time 10 mins
Cook Time 75 mins
Rest Time 10 mins
Total Time 95 mins
Servings 6 to 8 servings
Yield 1 (9x13-inch) casserole

Ingredients

  • Cooking spray

  • 1 tablespoon vegetable oil

  • 2 (8-ounce) ham steaks, cut into 1/2-inch pieces (about 3 cups)

  • 1 medium yellow onion, chopped (about 1 cup) 

  • 1 medium green bell pepper, chopped (about 1 1/4 cups)

  • 1 (16-ounce) package frozen shredded hash browns, thawed 

  • 4 ounces sharp pepper Jack cheese, shredded (about 1 cup) 

  • 2 teaspoons kosher salt, divided 

  • 1/2 teaspoon black pepper, divided

  • 8 large eggs

  • 1 cup whole milk

  • 3/4 cup sour cream

  • 2 teaspoons hot sauce (such as Tabasco)

  • 2 ounces sharp Cheddar cheese, shredded (about 1/2 cup)

Method

  1. Preheat the oven to 350°F. 

    Lightly coat a 9x13-inch baking dish with cooking spray.

  2. Cook the ham and vegetables:

    Heat the oil in a large nonstick skillet over medium-high. Add the ham, onion, and bell pepper; cook, stirring occasionally, until the ham starts to brown and onions are translucent, about 10 minutes. Set aside.

    Ham cubes and bell pepper cubes cooked together in a pan for Denver omelette hashbrown casserole recipe

    Simply Recipes / Photo by Fred Hardy / Food Styling by Jennifer Wendorf / Prop Styling by Lindsey Lower
  3. Make the casserole: 

    Stir the hash browns, pepper Jack cheese, 1 1/2 teaspoons of the salt, and 1/4 teaspoon of the black pepper in a large bowl until combined. Evenly spoon the hashbrown mixture into the prepared dish. Top evenly with ham mixture. 

    Whisk the eggs, milk, sour cream, hot sauce, and remaining 1/2 teaspoon salt and 1/4 pepper in a large bowl until combined. Carefully pour the egg mixture over the ham mixture. Evenly sprinkle with Cheddar cheese. Cover with aluminum foil.

    Simple Tip!

    You can assemble this casserole in advance and refrigerate it, covered, for up to 12 hours before baking.

    Cheese added to casserole dish for Denver omelette hashbrown casserole recipe

    Simply Recipes / Photo by Fred Hardy / Food Styling by Jennifer Wendorf / Prop Styling by Lindsey Lower
    Egg and milk mixture added to casserole dish with the rest of Denver omelette hashbrown casserole recipe ingredients

    Simply Recipes / Photo by Fred Hardy / Food Styling by Jennifer Wendorf / Prop Styling by Lindsey Lower
  4. Bake: 

    Bake, covered, for 40 minutes. Remove the foil and bake uncovered until the center is set and the ham starts to brown, about 20 minutes. Remove from the oven and let the casserole stand 10 minutes before serving.

    Love the recipe? Leave us a review and stars below!

    Baked Denver omelette hashbrown casserole in a casserole dish

    Simply Recipes / Photo by Fred Hardy / Food Styling by Jennifer Wendorf / Prop Styling by Lindsey Lower
    Denver omelette hashbrown casserole in a casserole dish at a table setting with a serving on a plate, a cup of coffee, and a jar

    Simply Recipes / Photo by Fred Hardy / Food Styling by Jennifer Wendorf / Prop Styling by Lindsey Lower
Nutrition Facts (per serving)
464 Calories
30g Fat
22g Carbs
26g Protein
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Nutrition Facts
Servings: 6 to 8
Amount per serving
Calories 464
% Daily Value*
Total Fat 30g 39%
Saturated Fat 11g 54%
Cholesterol 247mg 82%
Sodium 1609mg 70%
Total Carbohydrate 22g 8%
Dietary Fiber 2g 7%
Total Sugars 4g
Protein 26g
Vitamin C 39mg 194%
Calcium 259mg 20%
Iron 2mg 11%
Potassium 597mg 13%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
Nutrition information is calculated using an ingredient database and should be considered an estimate. In cases where multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.