Tender eggs are baked with savory ham, melty cheese, and earthy sautéed mushrooms for a hearty, make-ahead breakfast that is golden, bubbly, will have everyone wandering into the kitchen asking, “What smells so good?” This is a breakfast egg casserole that everyone loves!

This simple low carb, no bread egg casserole is perfect for breakfast, brunch or dinner! Full of Mushrooms, Ham, and Cheddar Egg Bake has so many great flavors, and it’s great for Weekend Food Prep!

Ingredients for Breakfast Egg Casserole Recipe

• Butter: Provides fat for sautéing, helps mushrooms brown, and adds flavor richness. Olive oil can also be used.
• Baby Bella Mushrooms: Add earthy depth and umami, and sautéing removes excess moisture so the casserole isn’t watery. 
• Ham: Adds a salty, savory protein boost and balances the richness of the eggs and cheese. 
• Eggs: The base of the casserole, binding everything together while giving it a rich, custardy texture .
• Skim Milk: Lightens the texture of the eggs, keeps them moist, and prevents the casserole from being rubbery. 
• Salt and Black Pepper: Enhance and balance flavors so the casserole doesn’t taste flat.
• Cheddar Cheese: Melts into creamy pockets, adds bold cheesy flavor, and helps bind ingredients together.
• Dried Oregano: Brings a subtle herby aroma and Mediterranean flavor to complement ham and mushrooms. 
• Fresh Spinach: Adds freshness, nutrients, and a pop of color; balances the richness with a mild, earthy taste.

How to Make Ham and Cheese Breakfast Casserole

1. Prep: Preheat the oven and grease a casserole dish.
2. Sauté: Heat a skillet pan over medium heat and add the butter or oil, then add the mushrooms and cook without stirring until browned. Season with salt and pepper. Set aside.
3. Beat: Beat the eggs and milk in a large bowl with a whisk. Season with about 1/2 teaspoon salt and pepper to taste. 
4. Combine: Add in the ham, mushrooms, cheese, oregano and spinach to the egg mixture. Stir to combine.
5. Bake: Pour into the prepared baking dish and bake until a knife inserted into the middle comes out clean.