Slow Cooker Morning Casserole

Name: Slow Cooker Morning Casserole
Prep time: 20 min
Cook time: 7 h 30 min
Total time: 7 h 50 min
Yield: 12 slices
Ingredients: 2 tablespoons olive oil; 1 large onion diced; 1 bell pepper diced (any color); 1 teaspoon garlic powder; 1 teaspoon salt; 1/2 teaspoon freshly cracked black pepper; 1 (4 ounce) can diced green chiles; 12 large eggs; 1 cup whole milk; 1 teaspoon Dijon mustard; 1 (30 ounce) bag frozen hash browns, thawed and drained; 1 pound breakfast sausage cooked crumbled *substitute ham or turkey sausage*; 2 cups shredded sharp cheddar cheese (divided); non-stick cooking spray; Optional garnish chopped green onions, fresh chives, hot sauce

By Emma

Certified Culinary Professional

Published on 25 January 2026 • Recipe tested & approved

Layered breakfast casserole with sautéed peppers, onions, eggs, sausage, and hash browns cooked low and slow until set. Cheesy, hearty, hands-off. Uses green chiles for a mild kick. Swap sausage for turkey or extra veggies to lighten. The slow cooker melds flavors while freeing the stovetop. Cooking times vary by machine, watch for egg firmness and bubbling edges. Great for feeding a crowd or prepping night before. Comes out moist without sogginess if layering done right and eggs poured evenly. Pan prepped with oil or butter—no sticking allowed.

Prep: 20 min

Cook: 7h 30min

Total: 7h 50min

Servings: 12 slices

#slow cooker #breakfast #casserole #easy meals #overnight prep

Nothing like waking up to the smell of breakfast slow-cooked and ready when you are. Started with a scramble experiment years ago, always ended too wet or mushy. Learned layering hash browns first keeps them from steaming into unrecognizable slop. Sausage or ham for that savory edge—feel free to swap for turkey or plant-based if that’s your jam. Throw in peppers and onions for texture. Green chiles add that unexpected zest—no showy heat, just warmth. Dijon mustard in egg mix? Yeah, subtle but game-changing, stops eggs from being blah and rubbery. This is one of those all-day cooks that demands patience but pays off big. Worth every minute while you sleep or hustle in other parts of kitchen. A crowd pleaser, emergency breakfast savior, and foolproof if you follow the layering logic. Hands off after starting, which frees up the morning chaos.

Ingredients

2 tablespoons olive oil
1 large onion diced
1 bell pepper diced (any color)
1 teaspoon garlic powder
1 teaspoon salt
1/2 teaspoon freshly cracked black pepper
1 (4 ounce) can diced green chiles
12 large eggs
1 cup whole milk
1 teaspoon Dijon mustard
1 (30 ounce) bag frozen hash browns, thawed and drained
1 pound breakfast sausage cooked crumbled *substitute ham or turkey sausage*
2 cups shredded sharp cheddar cheese (divided)
non-stick cooking spray
Optional garnish chopped green onions, fresh chives, hot sauce

About the ingredients

Sweet onion and bell peppers bring needed moisture and crunch. Use fresh if you can, frozen will water down layers making soggy final product. Sub green chiles for jalapeños if you like heat, or canned mild for breadth of flavor without kick. Breakfast sausage is cozy classic; I like spicy for contrast, but mild works too. Swap sausage for cubed ham or turkey sausage for leaner options. Frozen hash browns—thawed and patted dry—avoid ice crystals or extra water; wet potatoes create gluey texture. Always use full-fat milk and whole eggs for richness. Dijon mustard might sound odd but don’t skip, it balances egg flavor. Cheese, sharp cheddar is traditional, but pepper jack adds little surprise. Grease the slow cooker generously, especially if old or ceramic lined, because sticking ruins texture and cleanup. Keep all ingredients prepped and ready, especially if layering multiple casseroles for guests.

Method

Start heating olive oil in a decent-size skillet over medium-high heat. Toss in onions and bell peppers. Listen for that sizzle and watch when the peppers start to soften but still hold shape around 5-7 minutes. Stir often but don’t mash. Sprinkle garlic powder, salt, and pepper. Near the end, fold in diced green chiles. Smells intoxicating here; slight tang, savory lift. Remove from heat once veggies are vibrant with slight translucence.
Crack all eggs into a large mixing bowl. Whisk briskly while adding milk and Dijon mustard. The mustard cuts the richness, keeps things from getting flat. Whisk until mixture is uniform, a few bubbles on top. No lumps. Set aside.
Prep slow cooker with a spray or a light butter rub—must prevent sticking, especially bottom layer.
Layer time. Start with half the frozen hash browns spread evenly. Next, crumble in half the cooked sausage or ham. Evenly distribute half the onion–pepper–chile mixture. Top this layer with one cup of shredded cheddar.
Repeat layers exactly: remaining hash browns, meat, veggies, and finish with last cup of cheese on top. The cheese seals moisture, forms a browned, slightly crispy crust during cook.
Pour the egg mixture slowly, aiming to cover all layers. Some soak in, some rest on top—it’s supposed to be loose. Avoid pouring too fast or unevenly; might create dry spots or soggy pools.
Toss lid on. Cook on HIGH for about 3 to 4 hours; edges should be set and bubbling slightly. Or low for about 7 to 8 hours, better if overnight. No peeking unless necessary, lets the steam do its magic.
Test doneness by poking the center with a fork or skewer; eggs firm, not runny. The hash browns should be tender but with slight bite, no ice crystals leftover. Remove lid carefully, sprinkle freshly chopped green onions or chives. Hot sauce if you want a little extra punch.

Cooking tips

Start with the saute—hear the sizzle, smell the onions and peppers transforming, the garlic powder blooming aromas. Don’t rush; onions translucent signals ready base. Green chiles at the end keeps their brightness. Egg mix must be smooth, no lumps—whisk like your life depends on it, air bubbles help fluff. Layering is the key—half, then half again, ending on cheese; stops potatoes from over-steaming and keeps everything balanced. Pour eggs evenly, slow steady; guesswork leads to raw patches or excess liquid pockets. Cook time varies—don’t slavishly follow clock, test doneness visually and with poke test. Edges set, slight browning, firm but yielding center means done. Low heat overnight is best for logistics but high works if you need breakfast asap. Let it sit 10 minutes before cutting, helps bind. Garnishes add color and freshness; don’t skip green onions. Hot sauce is optional but recommended to wake sleepy taste buds. Troubleshoot soggy bottom by increasing bottom layer hash browns – more buffering. Sticky sides? More grease or use slow cooker liner. Overcooked? Less time or lower heat next round. Once mastered, it’s a crowd pleaser and your breakfast weapon.

Chef's notes

💡 Start with hot oil in skillet. Toss diced onions and peppers in once oil shimmers. Listen for sizzle; peppers soften, don’t mush, about 5-7 mins. Garlic powder, salt, pepper added near the end keeps flavors bright. Fold green chiles in last, preserves their zing without burning. Cook just till translucent. No limp mush allowed.
💡 Whisk eggs with whole milk and Dijon mustard thoroughly. Mustard cuts egg richness, stops rubbery texture. Air bubbles in mix help fluffiness later. No lumps. Slow pour this gently to avoid dry spots or soggy puddles. Eggs should coat layers, not drown them. Layering evenly key to moist, tender center.
💡 Grease slow cooker thoroughly. Spray or butter. Non-stick crucial, especially on older pots. Bottom layer needs protection from sticking and burning. Use liner for extra security but spread grease if no liner. Stuck edges ruin casserole texture and cleanup.
💡 Layer hash browns first, half the bag, spread evenly. Follow with half cooked sausage or ham crumbles. Add onion-pepper-chile mix evenly next layer. One cup shredded cheddar seals moisture on each repeat. Cheese crust forms browned edge when done. Finish top with cheese. Avoid overcrowding layers, balance moisture and texture.
💡 Cook low overnight for 7-8 hours or high 3-4 hours. No peeking during cook to keep steam intact. Edges should bubble and brown lightly. Test doneness with fork poke; eggs firm, center not runny. Hash browns soft but still hold some bite. Let rest ten mins after cooking for binding. Garnish green onions or chives, optional hot sauce for punch.

Common questions

Can I swap sausage for turkey?

Sure, turkey works. Leaner protein option. Less fat, so casserole might be drier. Add a bit more oil or cheese to balance. Ham also fine. Keep meat cooked crumbly before layering. Spicy or mild depends on preference.

How to avoid soggy casserole bottom?

More hash browns bottom layer. Spread thin and evenly. Frozen potatoes need drying; water pools cause gluey texture. Grease slow cooker bottom well. Liner helps or extra butter spray. Avoid overcrowding layers. Cook time too long can also cause sogginess.

What if eggs are runny in center?

Cook longer low or high. Fork poke test best. Runny means not firmed yet. Pour egg mix slowly next time; even coverage helps. Could be slow cooker temp variations. Let sit ten mins after cooking, carryover heat finishes eggs.

How to store leftovers?

Refrigerate in airtight container. Keeps 3-4 days. Reheat covered in oven or microwave. Freeze individual slices wrapped tightly, thaw overnight in fridge before warming. Texture changes slightly but still tasty. Avoid freezer burn.