Bursting with incredible flavor, this high protein breakfast casserole combines eggs, lots of colorful vegetables, and savory bacon layered over a crispy sweet potato crust. Easy to prep ahead for holidays, brunches, or busy mornings.

Make-Ahead Breakfast Casserole serving on a plate with a bite on a fork, chili crunches on side

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I created this Breakfast Casserole so we could wake up to a delicious, healthy meal on Thanksgiving morning when the kitchen is already buzzing with feast preparations. It’s quickly become my go-to on any busy day when I crave ease and simplicity.

This breakfast casserole is bursting with delicious flavors and a variety of textures but is easy to prep ahead. It’s a versatile recipe packed with high-protein eggs, savory bacon (or turkey bacon), lots of nutrient-rich vegetables, fresh herbs and healthy carbs from the sweet potato crust.

Perfect for Thanksgiving or Christmas morning, weekend brunch, or busy weekdays. Colorful, satisfying, and totally customizable. Just slice, warm, and enjoy an easy satisfying start to your day—everyone loves it!

Why You’ll Love This Make-Ahead Breakfast Casserole

Incredible Flavor — Fresh herbs, savory bacon, and a variety of vegetables create a vibrant depth of flavor in every bite.
High-Protein & Energizing — Packed with protein from eggs and bacon (or turkey bacon) to keep you satisfied and energized all morning.
Loaded with Vegetables — Filled with colorful, nutrient-rich vegetables that add flavor, texture, and feel-good nourishment.
Sweet Potato Crust — A wholesome alternative to bread, offering steady energy and delicious natural sweetness.
Versatile & Customizable — Swap in your favorite vegetables, herbs, or cheeses to match your taste or what’s in your refrigerator. Leave out bacon for vegetarian..
Make-Ahead Magic — Prepare the day before so your morning feels peaceful and effortless—perfect for Thanksgiving or any busy weekday.
Gluten-Free & Paleo-Friendly — Naturally grain-free with dairy-free options.
Crowd-Pleaser — Ideal for brunch gatherings, holidays, or family weekends; everyone loves it.
Easy to Reheat — Stays delicious for days, reheats perfectly, and makes meal prep feel joyful and simple.

Breakfast Casserole Recipe Ingredients

Pastured eggs — the protein-rich base that binds everything together and keeps you full.
Shredded sweet potatoes — creates a naturally sweet crust with healthy carbs for energy, and beautiful color. Use the large holes of a box grater or shredding attachment on a food processor. Butternut squash can be substituted.
Cremini mushrooms — adds umami richness and hearty texture. Use any mushroom you like.
Scallions — bring brightness and gentle onion flavor, onions can be substituted.
Radicchio or bell peppers — colorful, antioxidant-packed vegetables that add complexity and balance. The colored vegetables add nutrients and contrast.
Broccoli florets — nutrient-dense greens that hold their shape and add a fresh bite.
Bacon or turkey bacon — smoky, salty flavor and additional protein to make the casserole satisfying. Leave out for vegetarian.
Half & Half, milk or dairy-free milk — makes the egg mixture fluffy and custardy.
Fresh marjoram or oregano — vibrant herbal flavor that elevates the whole dish. I love the taste of marjoram but it’s often hard to find. I’ve also made it with dill.
Shredded cheese (optional) — adds richness and a melty, creamy finish if desired. I like gruyere, cheddar or manchego.

Make-Ahead Breakfast Casserole ingredients

Variations and Dietary Substitutions

This is a versatile recipe, here are some ideas for variations:

Turkey Bacon or Breakfast Sausage — Swap the bacon for turkey bacon or crumbled breakfast sausage for a different flavor and protein boost.
Vegetarian — Omit the bacon and add chickpeas, black beans, or more mushrooms for hearty plant-based protein.
Dairy-Free — Use coconut milk or almond milk and skip the cheese or use your favorite dairy-free alternative.
Vegetable Substitutions — Cauliflower, red or green peppers, red cabbage or whatever you have in your refrigerator.
Mediterranean Style — Add olives, sun-dried tomatoes, roasted red peppers, and oregano; finish with feta (or dairy-free feta).
Spicy Southwest — Add jalapeños, chili powder, cumin, smoked paprika and fresh cilantro; serve with salsa and avocado.
Add Greens — Add in extra greens like kale, spinach, and zucchini. Cook them with the other vegetables.
Herb Substitutions – Use fresh basil or parsley.
Low-Carb Option — Skip the sweet potato crust and bake directly in a greased dish for a lighter, keto-friendly version.
Mushroom Lover’s Version — Use a mix of wild mushrooms like shiitake, cremini, and oyster mushrooms for deeper umami richness.
Holiday Brunch Style — Add cranberries and rosemary for a festive twist.

Make-Ahead Breakfast Casserole 2 plates with serving of casserole, avocado and sprouts

How To Make This Breakfast Casserole with Photos

Roast the bacon and potatoes. Toss the shredded sweet potatoes on a baking sheet with olive oil, garlic powder, thyme, salt, and black pepper. On another baking sheet place the slices of bacon. Put both sheets into the oven and roast for 20 minutes or until the bacon is crispy and the sweet potatoes are beginning to soften and a little crispy.

Make-Ahead Breakfast Casserole shredded sweet potatoes and bacon on baking sheet

Sauté the vegetables. Heat olive oil in a large saute pan. Add mushrooms and a pinch of salt and saute for 4 minutes until they begin to soften. Add the scallions. Saute 1 minute. Add the broccoli and radicchio. Saute 2 minutes. Set aside to cool.

Make-Ahead Breakfast Casserole vegetables cooked in saute pan

Lay down the sweet potato layer. Oil a 7” x 11” pan and lay the shredded sweet potatoes on the bottom, press to make sure they’re spread out evenly.

Make-Ahead Breakfast Casserole shredded potatoes in casserole dish

Mix the eggs. In a large bowl whisk together the eggs, milk and a little salt and pepper. Add the cheese if using and the marjoram. Mix until evenly combined.

Make-Ahead Breakfast Casserole eggs in a bowl with marjoram and cheese

Add bacon. Crumble the bacon and add it to the vegetables, mix to combine. Spread on top of the potatoes.

Make-Ahead Breakfast Casserole - High Protein crumbled bacon

Make-Ahead Breakfast Casserole - High Protein mixed vegetables and bacons in casserole

Pour in the egg mixture and bake. Pour the egg mixture over the vegetables. Bake uncovered until set, 35-45 minutes.

Make-Ahead Breakfast Casserole - High Protein in casserole uncooked

Make Ahead and Storage Tips

Make-ahead tip: If you want to cook the casserole the morning you’re eating it. You can prepare the shredded sweet potatoes, bacon, and vegetables and layer the casserole dish without the eggs and cheese. Cover with plastic wrap and store in the refrigerator the night before. Then, remove it from the refrigerator to let it come to room temperature. Whisk the eggs, with herbs and cheese, pour into the casserole and bake.
To store: Store leftovers covered in the refrigerator for 4 to 5 days. Reheat when ready to eat.
To freeze and reheat: Cook, cool and cut the casserole. Store an airtight container in the freezer for up to 3 months. To serve, thaw overnight in the refrigerator. Bake covered, in a 350° oven for 30 minutes. You can do one piece or the whole casserole.

Make-Ahead Breakfast Casserole - High Protein baked in tray sitting on a napkin.

What to Serve With Breakfast Casserole

Certainly you can eat this breakfast casserole alone or with a few slices of avocado and sprouts. It’s nutritious and satisfying. If you’re entertaining, here are a few recipes that are make it even more wonderful. Everyone will be so happy!

Pumpkin Scones or Raspberry Lemon Scones
Apple Coffee Cake or Pumpkin Coffee Cake
Cranberry Orange Muffins, Pistachio Muffins or Pumpkin Chocolate Chip Muffins
Cinnamon Raisin Bread, Banana Bread or Olive Oil Zucchini Bread

I hope you love this delicious, nutritious, high protein breakfast casserole. It will bring ease and joy to your mornings, whether it’s a holiday celebration or an ordinary busy day.

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