Overnight egg casserole
Bread, browned mushrooms, spinach and two cheeses soaked overnight in custard, then baked puffy and golden, so the work is done before you get hungry.
- 575 min total
- 30 min hands-on
- Follow-a-recipe easy
- Serves 8
- About $2.03 a serving
- 440 calories
- Good the next day
- Vegetarian
Dolly says: Make the full amount. It’s just as good for lunch the next day.
Ingredients
For 8 servings.
- 1 French bread, about 12 oz
- 8 oz baby bella mushrooms, sliced
- 1 yellow onion, diced
- 3 tbsp butter, divided
- 1 package baby spinach, 5 oz
- 1 cup Swiss cheese, shredded
- 1 cup shredded cheddar
- 10 large eggs
- 2½ cups milk
- 1 tbsp Dijon mustard
From your pantry
- 1 tsp salt, divided
- ½ tsp black pepper
Each serving has about 440 calories, 24 g protein, 35 g carbs and 22 g fat, and costs about $2.03 at typical US grocery prices. Both are estimates from what the recipe uses.
Missing something?
- No French bread? Sourdough bread works.
- No baby bella mushrooms? White mushrooms work.
- No yellow onions? White onions or red onions work.
- No butter? Ghee works.
- No baby spinach? Kale or arugula works.
- No shredded cheddar? Cheddar cheese or Mexican blend cheese or Monterey Jack cheese works.
- No milk? Half-and-half works.
Steps
Tap an underlined word for a quick explanation.
Cut the bread into 1-inch . the mushrooms and the onion.
Cube. Cubing means cutting food into chunky, even squares, usually three quarters of an inch to an inch. Same-size cubes cook at the same speed and brown on every side.
How you’ll know: Your pieces look like a handful of sugar cubes, a little bigger than diced, all close to the same size.
Slice. Slicing means cutting food into flat pieces of about the same thickness. Even slices cook evenly, so none are raw while others burn.
How you’ll know: Lay a few side by side: they’re close to the same thickness from one end to the other.
Dice. Dicing means cutting food into small, even cubes, usually a quarter to half an inch across. Pieces the same size cook at the same speed, so nothing burns while the rest catches up.
How you’ll know: Your pieces are little cubes about the size of a chickpea, and they all look close to the same.
2 tablespoons butter in a large over medium-high heat. Cook the mushrooms and onion, stirring now and then, until browned and their liquid is gone, 8 to 10 minutes.
Melt. Melting means gently heating something solid, like butter or cheese, until it turns liquid. Low or medium heat keeps it from browning or burning.
How you’ll know: It’s smooth and liquid, and butter may foam a little but hasn’t turned brown.
Skillet. A skillet is a frying pan: wide and flat with low, sloped sides. The shape lets steam escape, so food browns instead of stewing.
How you’ll know: It’s the pan you’d fry an egg in, and a 10 or 12 inch one handles most recipes.
Medium-high heatTimer: 9 min
Add the spinach a handful at a time and stir until . Season with ½ teaspoon salt.
Wilt. Wilting means cooking leafy greens just until they go soft and collapse. Greens shrink a lot, so a big pile of spinach becomes a small handful, and that’s normal.
How you’ll know: The leaves turn soft and deep green and slump into the pan, usually within a minute or two.
Medium-high heat
Butter a 9x13 baking dish with the rest of the butter.
Spread in half the bread, then half the vegetables and half of each cheese.
Repeat the layers.
the eggs, milk, mustard, the rest of the salt and the pepper, then pour it evenly over the top. Press the bread down so it soaks up the custard.
Whisk. Whisking means beating quickly with a whisk or a fork to blend things together. It smooths out lumps and mixes eggs, oil or sauces evenly.
How you’ll know: It all looks one even color and texture, with no streaks or lumps.
Cover and refrigerate for at least 8 hours or overnight.
Timer: 480 min
Dolly’s tip: This is the secret. The bread drinks up the custard overnight and bakes up puffy and soft, not dry.Take the dish out of the fridge and the oven to 350°F.
Preheat. Preheating means turning the oven on before you start, so it’s fully hot when the food goes in. Food that starts in a cold oven cooks unevenly and doesn’t brown the same.
How you’ll know: The oven beeps or its light clicks off, usually 10 to 15 minutes after you turn it on.
uncovered 50 to 60 minutes, until puffed and and a knife in the center comes out clean.
Bake. Baking means cooking in the oven with dry heat all around the food. It cooks evenly from every side, so you can mostly leave it alone.
How you’ll know: It’s golden on top and passes the recipe’s check, like a clean toothpick or the right temperature.
Golden brown. Golden brown is the color of good toast, somewhere between yellow and light brown. It means the outside is cooked and crisp but not burnt.
How you’ll know: It looks like toast and smells toasty; dark brown with a bitter smell means it went too far.
Timer: 55 min
Dolly’s tip: If the top browns too fast, lay a sheet of foil loosely over it.Food safety: For the safest eggs, cook until the whites are fully set and the yolks begin to thicken. Dishes made with eggs are done at 160°F.
Let it 10 minutes before cutting.
Rest. Resting means letting cooked meat sit for a few minutes before you cut it. It keeps cooking gently, and more of the juice stays in the meat instead of running onto the board.
How you’ll know: Loosely covered with foil, it stays hot, and very little juice runs out when you slice it.
Timer: 10 min
Plan this in Dollop, and get the grocery list
Dollop puts this dinner on a night that suits your week, lists only what you still need to buy, and walks you through each step while you cook.
More dinners like this
Slow cooker hash brown egg casserole
315 min
Tater tot breakfast casserole
70 min
Freezer breakfast burritos
50 min
Sheet pan frittata
45 min
Vegetarian dinners ›Cozy comfort food ›What to make with eggs and cheddar ›What to make with eggs and spinach ›What to make with eggs and Swiss cheese ›