5-Ingredient Keto Breakfast Casserole

If your mornings look like a sprint between coffee, lost keys, and a questionable banana, I’ve got your new bestie: a 5-ingredient keto breakfast casserole. It’s hearty, low-carb, and ridiculously easy. No fancy gadgets, no culinary degree, just five ingredients and a pan. Make it once, eat well for days, and feel smug about your life choices.

Why This Casserole Wins Mornings

You know those breakfasts that taste great but require 14 steps and a prayer? Not this one. You toss five real ingredients into a dish, pop it in the oven, and boom—breakfast for the week. It’s simple, repeatable, and honestly, kind of addictive.
Plus, it’s keto without feeling like “diet food.” You get savory, cheesy goodness that keeps you full, focused, and out of the snack drawer. FYI, this also survives the dreaded reheat test like a champ.

The 5 Essential Ingredients

Let’s keep the promise: five items. That’s it. Here’s the base that never fails:

• Eggs – The star. They bind everything and bring protein.
• Breakfast sausage (pork or chicken) – Crumbled and cooked. Adds fat, flavor, and serious satisfaction.
• Shredded cheese – Cheddar, mozzarella, or a blend. Cheese = structure + melty bliss.
• Heavy cream – Makes the eggs custardy and rich. Yes, please.
• Spinach or broccoli – A little greenery so we can say “balance” with a straight face.

Optional but excellent: Salt, pepper, garlic powder, and red pepper flakes. I’m not counting these as ingredients because IMO seasonings are non-negotiable.

How to Make It (No Drama, Just Breakfast)

This is almost too easy. Almost.

1. Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking dish.
2. Cook the sausage in a skillet until browned. Drain excess fat if needed.
3. Prep the greens: If using spinach, wilt it in the sausage pan for 1-2 minutes. If using broccoli, steam or microwave until just tender.
4. Whisk the eggs with heavy cream. Season with salt, pepper, and garlic powder.
5. Assemble: Spread sausage and greens in the dish. Sprinkle most of the cheese over. Pour egg mixture on top. Finish with remaining cheese.
6. Bake 28–35 minutes, until the center sets and the edges turn golden. Let it rest 5–10 minutes, then slice.

Ingredient Ratios That Work

If you’re a numbers person, here’s the sweet spot for a 9×13:

• 10–12 large eggs
• 1 lb breakfast sausage
• 1 cup heavy cream
• 2 cups shredded cheese
• 2 packed cups spinach (or 1.5 cups chopped broccoli)

Tip: Want it ultra-rich? Use 12 eggs and 1.25 cups cream. Want it lighter? Do 10 eggs and 3/4 cup cream.

Flavor Moves (Still 5 Ingredients, Promise)

You can switch the core ingredients while staying within the “five” rule. Pick a lane and drive it.

• Meat swap: Bacon, chorizo, or turkey sausage.
• Cheese swap: Pepper Jack for heat, Gruyère for fancy vibes, mozzarella for stretchy comfort.
• Veg swap: Mushrooms (sauté first), bell peppers, or asparagus tips.

Three Killer Combos

• Southwest: Chorizo + Pepper Jack + spinach + a pinch of cumin.
• Florentine: Italian sausage + mozzarella + spinach + a dusting of nutmeg.
• Bacon & Broccoli: Crispy bacon + cheddar + broccoli + black pepper.

IMO, the chorizo version makes Monday feel like Saturday.

Macros and Keto-Friendliness

Yes, it’s truly keto, not “keto-ish.” Here’s the ballpark per serving (8 slices from a 9×13) using sausage, spinach, cheddar, and heavy cream:

• Calories: ~350–400
• Fat: 26–32g
• Protein: 20–24g
• Net carbs: ~2–4g

Heads up: Veggies can shift carbs a bit. Spinach stays lower than bell peppers. Choose what fits your goals and your taste buds.

Meal Prep: Make It Once, Win All Week

Casseroles practically beg for meal prep. Here’s how to keep it fresh and tasty day after day.

• Storage: Cool completely. Slice and store in airtight containers for up to 4 days.
• Reheat: Microwave 60–90 seconds per slice or warm in a 300°F oven for 8–10 minutes. It holds texture well either way.
• Freezer-friendly: Wrap slices individually. Freeze up to 2 months. Thaw overnight in the fridge before reheating.

Serving Ideas That Keep It Fun

• Fresh toppings: Dollop of sour cream, sliced avocado, chopped chives.
• Heat lovers: Hot sauce, chili crisp, or a light drizzle of chipotle mayo.
• Brunch upgrade: Side salad with lemony vinaigrette to cut the richness.

Common Mistakes (And Easy Fixes)

Let’s dodge the usual traps so your casserole turns out dreamy every time.

• Watery results: Overloaded veggies leak moisture. Sauté mushrooms, wilt spinach, and drain sausage well.
• Rubbery texture: You baked it to oblivion. Pull it when the center just sets and barely jiggles.
• Flat flavor: You skipped seasoning. Salt and pepper matter, and a tiny pinch of garlic or onion powder works wonders.
• Grease pools: Use moderately fatty sausage or drain excess fat before assembling.

Make It Work For Your Diet

Got preferences or allergies? You can still enjoy this with a few tweaks.

• Dairy-free: Use coconut cream instead of heavy cream and a good dairy-free shredded cheese. Texture stays rich.
• No pork: Turkey sausage or chicken chorizo keeps flavor high.
• Vegetarian: Skip the meat and add extra veggies plus a handful of chopped nuts for crunch. Protein drops, but it’s still tasty.
• Spice control: Keep it mild for kids, then add hot sauce to your own slice. Win-win.

FAQ

Can I prep this the night before?

Yes. Assemble everything in the dish, cover, and refrigerate overnight. In the morning, let it sit on the counter for 15 minutes while the oven preheats, then bake as usual. Expect it to need an extra 5 minutes in the oven since it starts cold.

Do I need to line the pan with parchment?

You don’t need to, but it makes cleanup easier. A good spray of avocado oil or butter works fine. If your pan loves to stick, parchment’s a safe bet.

How do I keep it from turning soggy?

Cook and drain the sausage, wilt or pre-cook watery veggies, and avoid overly juicy add-ins like tomatoes unless you seed them. Also, let the casserole rest after baking so it sets properly.

Can I make a smaller batch?

Totally. Halve everything and use an 8×8 dish. Start checking doneness around 22 minutes. Same golden edges, same creamy center, just less of it (sad, but practical).

What if I don’t have heavy cream?

Use half-and-half, or whisk in a tablespoon of melted butter per cup of milk to boost fat. It changes the texture slightly but still tastes great. FYI, full-fat options keep it more keto-friendly.

What cheese melts best?

Cheddar melts nicely and brings flavor. Mozzarella stretches but tastes milder. Monterey Jack lands in the middle and plays well with everything. IMO, a cheddar–mozz blend hits the sweet spot.

Conclusion

This 5-ingredient keto breakfast casserole checks every box: fast, flexible, and wildly satisfying. You can riff on flavors, prep it ahead, and eat like a champ all week. Keep the ingredients simple, season generously, and don’t overbake. Breakfast, handled. Now go find those keys.