Breakfast Casserole with Hash Browns
This breakfast casserole with hash browns layers grated boiled potatoes, sautéed brown mushrooms, and sharp Cheddar under a savory egg-and-milk custard, then bakes until the top turns golden. It is a filling vegetarian breakfast bake that comfortably feeds 6 to 8 people, and it comes together with pantry staples and one dish. If you want a warm, hearty way to start the day, or something to set on the table when the whole family is hungry at once, this is it.
I love to prepare veggie casseroles. I usually make them when I have guests, because they are an ideal solution to feed several people at once without spending the whole morning at the stove. You do a little chopping, a little layering, and the oven does the rest.
Why You’ll Love This Hash Brown Breakfast Bake
It is a one-dish meal, so cleanup stays minimal. It scales up easily for a crowd, which makes it perfect for a weekend brunch or a holiday morning. The layers of potato, mushroom, and cheese give you a satisfying, savory bite in every forkful, and because it bakes low and slow, the custard sets soft while the top crisps. If you like this style of hearty morning cooking, you will find plenty more in my collection of breakfast casserole recipes and my broader brunch recipes.
What You’ll Need
The ingredient list is short and forgiving. Here is what each part brings to the dish:
- Boiled potatoes, grated — the base of the casserole. Boiling them first, then grating, gives you a tender hash-brown texture that holds together as it bakes.
- Brown mushrooms — chopped and sautéed until browned, they add an earthy, savory depth that stands in beautifully for meat.
- Cheddar, grated — sharp Cheddar melts into the layers and forms that golden top. A well-aged cheese gives the most flavor.
- Eggs and full-fat milk — whisked together, they become the custard that binds everything and puffs slightly in the oven.
- Garlic powder and onion powder — season the mushrooms so every layer tastes seasoned, not flat.
- Olive oil, salt, and pepper — for greasing the dish, sautéing, and seasoning the custard.
Tips for Getting the Layers Just Right
A few small habits make the difference between a soggy bake and a golden one:
- Cool the mushrooms first. Transfer the sautéed mushrooms to a bowl and let them cool before layering, so they do not start cooking the eggs early.
- Cook off the mushroom moisture. Fry them until they are properly browned, not just softened. That extra minute keeps excess water out of the casserole.
- Layer in order. Grated potatoes first, then the mushroom layer, then the cheese, and pour the egg mixture over the top last so it can seep down through everything.
- Watch the top, not just the clock. It usually takes 35 to 40 minutes at 180 C (375F), but pull it when the top turns golden and the center is set.
Make Ahead, Store, and Reheat
This casserole is a good make-ahead dish. You can assemble the layers the night before, cover the dish, and keep it in the fridge, then pour the egg mixture over and bake in the morning. Once baked, let leftovers cool, cover, and refrigerate for up to three or four days. Reheat individual portions in the oven or microwave until warmed through. It also holds well at room temperature on a brunch table, which is part of why I reach for casseroles when guests are coming. For another egg-forward option along the same lines, try my easy egg bake casserole.
What to Serve With It
Because it is rich and savory, a fresh side balances it nicely. A simple green salad, sliced tomatoes, or some fruit on the side rounds out the plate. If you are building a bigger spread, add something sweet alongside, like a cinnamon roll casserole, so guests get both ends of the breakfast table. This bake sits comfortably within classic American cuisine, so it pairs well with the usual weekend brunch favorites.
If you make this breakfast casserole with hash browns, I would love to know how it turned out. Give the recipe a star rating below and leave a comment telling me whether you kept it classic or added your own twist — it helps other readers and it always makes my day.
Summarise & Save This Recipe
★ Add us as a trusted Google source
Breakfast Casserole with Hash Browns
Ingredients
- 5 large boiled potatoes grated
- 2 tablespoons olive oil
- 2 cups brown mushrooms chopped
- ½ teaspoon garlic powder
- ½ teaspoon onion powder
- 2 cups Cheddar grated
- 6 eggs
- ½ cup full-fat milk
- 1 teaspoon salt
- 1 teaspoon pepper
Instructions
- Heat the oven to 180 C (375F).
- Grease a casserole dish with 1 tablespoon of olive oil
- In a frying pan, over medium heat, add 1 tablespoon of the remaining oil, the chopped mushrooms, onion powder and garlic. Fry, stirring from time to time, until the mushrooms are browned.
- Transfer the cooked mushrooms to a bowl to cool.
- In a separate bowl, add eggs, milk, salt and pepper. Mix with a whisk, until it becomes a homogeneous composition.
- Now place the grated boiled potatoes in the casserole, in layers, then put the cooked mushrooms in one layer, cover with the cheese layer and then pour the egg mixture over it.
- Put it in the oven and let it cook for 35-40 minutes, or until the top layer turns golden.
Frequently Asked Questions
Yes. It is made with grated boiled potatoes, brown mushrooms, Cheddar cheese, eggs, and milk, so there is no meat in it. It is vegetarian but not vegan, since it contains eggs and dairy.
Yes. You can layer the potatoes, mushrooms, and cheese the night before, cover the dish, and refrigerate it. In the morning, pour the whisked egg-and-milk mixture over the top and bake as directed. This makes it convenient for holidays or when you have guests.
The recipe uses large boiled potatoes that are grated to create the hash-brown base. Boiling the potatoes first and then grating them gives a tender texture that holds together well as the casserole bakes. Starchy or all-purpose potatoes both work fine.
Bake it at 180 C (375F) for about 35 to 40 minutes. It is ready when the top layer turns golden and the egg custard in the center is set and no longer runny. Because ovens vary, watch the color of the top rather than relying only on the timer.
Let the casserole cool, then cover it and keep it in the fridge for up to three or four days. Reheat individual portions in the oven or microwave until warmed through. It also holds well at room temperature for a while, which makes it handy for a brunch table.
Yes. The mushrooms add a savory, meaty depth, but you can use whatever mushrooms you have or add other cooked vegetables. Cheddar gives a sharp, golden top, though another good melting cheese will work too. Just keep the potato, egg, and milk base the same so the casserole still sets.
