
If you’re after a no-hassle morning dish that wins over a crowd, this Slow Cooker Breakfast Casserole with Mushrooms might be exactly what you need. You get a cozy mix of fluffy eggs, hash browns, juicy mushrooms, loads of cheddar, and you can toss in bacon or sausage depending on your vibe. It’s pure comfort for holiday brunch or a lazy weekend since you just set it up and move on with your day. I always have this simmering when family’s around so I can enjoy time together instead of working in the kitchen.
This became our go-to on Christmas morning and now nobody will let me skip it. I just let it cook away while we hang out and by the time folks arrive, it’s all warm and waiting for us.
Savory Ingredients
- Large eggs: They hold everything together and keep that traditional casserole feel. Go with eggs that look and smell fresh if you can.
- Garlic powder: Adds a quick savory punch and ties everything together. Plain garlic powder is best—no hidden salt needed.
- Salt: Brings out the other flavors. Add the amount you like.
- Fresh parsley or green onions for garnish: Toss these on at the end for a pop of green and extra fresh taste.
- Milk: Mixes with the eggs for creamy results. Any milk’s fine, but whole milk is especially rich.
- Mushrooms: Slice them up—they soak up all the seasonings and add a nice, chewy texture. Pick firm mushrooms without wet spots.
- Onion: Adds a sweet undertone. Look for onions that are heavy and firm.
- Shredded cheddar cheese: Melts into everything. Buy a block and grate it for the best melt.
- Black pepper: Freshly cracked gives the most gentle heat and aroma.
- Breakfast sausage or bacon: Fry until crispy then break it up. You can go classic or pick your favorite, just use good meat for max flavor.
- Frozen hash browns: Toss in yellow or white hash browns—cube for a chunkier bite or shredded for creamy. Look for simple ingredients on the label.
- Bell pepper: Chopped for a little crunch and color. Bright, firm ones are best.
- Paprika: Sprinkled in for color and just a hint of warmth. Smoked paprika gives a deeper flavor if you want.
Easy Steps
- Serve:
- Switch off your slow cooker, let the dish cool down for about ten minutes before you slice. A sprinkle of green onions or parsley looks awesome and I always pop hot sauce nearby for anyone who’s into spicy.
- Cook:
- Close the lid and cook on high for three to four hours or on low overnight for seven to eight hours. You’ll know it’s ready when the eggs don’t look jiggly and a knife poked in the center comes out clean. Try not to peek too much or you’ll lose heat.
- Pour On the Eggs:
- Slowly drizzle your egg mix all over your layers. Use a spatula to mash things gently so everything’s soaked and covered. Make sure there’s no dry spots on the top.
- Whisk the Egg Mix:
- Grab a big bowl and whisk eggs, milk, garlic powder, paprika, black pepper, and salt all together. Go until the yolks break up and you see the spices all through.
- Build Your Layers:
- Toss half the frozen hash browns on the bottom of your crockpot. Layer on half the sausage or bacon, onion, bell pepper, mushrooms, and cheddar. Repeat the stacks with the rest of your stuff. This keeps every bite packed with goodness.
- Brown the Mushrooms:
- Sear the mushrooms in a hot pan—don’t crowd them or they’ll steam instead of getting brown. Stir every now and then and stop after about three to five minutes, once they’ve softened and shrunk.
- Get the Cooker Ready:
- Coat the inside of your slow cooker with spray or rub it with a bit of soft butter. This keeps everything from sticking and makes cleanup a breeze.

Mushrooms really shine here since they grab up all the flavor and add something special to every bite. My kids say it’s the best breakfast going and I love how hungry it makes everyone for breakfast together.
Smart Storage
Pop any leftovers in a sealed container and stick in the fridge for up to three days. Microwave gently or heat in a low oven whenever you want some. You can also freeze slices for up to two months—just wrap them in foil first, then into a freezer bag.
Swaps & Variations
Switch out sausage for a plant-based version or go lighter with turkey sausage if you want. If cheddar’s not your thing, use mozzarella or pepper jack—they melt well too. Try kale if you want to change up the veggies instead of bell peppers.

How to Serve
Dish up each piece with some hot sauce or salsa. Add sliced fruit on the side for freshness. Want to fancy things up? Throw on a handful of extra herbs or a few slices of avocado right on top.
Tradition & Background
This kind of breakfast casserole is super common for American brunch, especially at big family get-togethers or holidays. The slow cooker version showed up when folks wanted breakfast ready to go with no morning work. It’s classic comfort meets modern convenience, and that’s why families love it for holidays and busy weekends alike.
Frequently Asked Questions About Recipes
- → Can I swap in bacon for sausage?
For sure! Go with bacon, sausage, or both—do whatever makes your morning better.
- → What's the trick to keeping it from sticking?
Before you start, rub some butter or non-stick spray all around your slow cooker. That'll stop it from sticking later.
- → Is this something I can set up before bed?
Definitely. Just toss everything together at night and leave it in the fridge until you're good to cook.
- → Which veggies are good in this?
Spinach, tomatoes, diced zucchini, or your favorite veggies—any of those are great swaps or add-ons for mushrooms.
- → Can I shred my own potatoes instead of using frozen?
Yep! Shred some fresh potatoes and dry them off before using. That helps keep the texture nice.
- → How do I know when it's cooked through?
You’ll know it’s ready when the middle is firm and a knife poked in the center comes out clean.