Leftover Ham Breakfast Casserole – A Cozy, Make-Ahead Morning Favorite

Leftover ham has a way of lingering in the fridge after a holiday or big Sunday dinner. This easy breakfast casserole turns those extra slices into a hearty, crowd-pleasing meal. It’s warm, comforting, and simple enough to pull together before coffee kicks in.

You can build it the night before, pop it in the oven in the morning, and let the kitchen smell amazing while you ease into the day. It’s a reliable way to feed a family or a small group without fuss or fancy techniques.

Leftover Ham Breakfast Casserole - A Cozy, Make-Ahead Morning Favorite

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Prep Time 15 minutes mins

Cook Time 45 minutes mins

Total Time 1 hour hr

Servings: 8 servings

Ingredients Method

Ingredients

  

• 4 cups cubed day-old bread (sourdough, French, or whole wheat)
• 2 cups cooked ham, diced
• 1 cup shredded sharp cheddar (or a mix with Swiss or Monterey Jack)
• 8 large eggs
• 2 cups milk (whole or 2%; use 1 1/2 cups milk + 1/2 cup cream for richer texture)
• 1 cup vegetables, chopped (such as bell pepper, onion, spinach, or mushrooms)
• 2 tablespoons butter or olive oil (for sautéing vegetables and greasing the dish)
• 1 teaspoon Dijon mustard (optional but recommended for flavor depth)
• 1/2 teaspoon garlic powder
• 1/2 teaspoon onion powder
• 1/2 teaspoon dried thyme or Italian seasoning
• 1/2 teaspoon kosher salt
• 1/2 teaspoon black pepper
• 2–3 tablespoons chopped fresh herbs (optional: parsley or chives)

Method

 

1. Prep the pan: Grease a 9x13-inch baking dish with butter or oil. Preheat your oven to 350°F (175°C) if baking right away.
2. Toast the bread (optional but helpful): If your bread is very soft, spread the cubes on a sheet pan and toast at 300°F for 8–10 minutes to dry them slightly.This helps the casserole set.
3. Sauté the veggies: Warm a skillet over medium heat with butter or oil. Cook onions and peppers 3–4 minutes until softened. If using mushrooms, cook until their moisture evaporates.Stir in spinach last and wilt briefly. Let cool slightly.
4. Whisk the custard: In a large bowl, whisk eggs, milk, Dijon, garlic powder, onion powder, thyme, salt, and pepper until smooth.
5. Layer the base: Add bread cubes to the baking dish. Scatter ham and sautéed vegetables over the top.Sprinkle most of the cheese evenly.
6. Add the custard: Pour the egg mixture over everything, pressing down gently so the bread absorbs the liquid. Top with the remaining cheese.
7. Rest time: Let it sit 10–15 minutes at room temperature, or cover and refrigerate overnight for the best texture.
8. Bake: If chilled, uncover and bake 45–55 minutes at 350°F, until the center is set and the top is golden. If baking right away, start checking at 40 minutes.A knife inserted near the center should come out clean.
9. Finish and serve: Rest 10 minutes before slicing. Sprinkle with fresh herbs and serve warm.

Why This Recipe Works

• Smart use of leftovers: Ham adds salty, savory flavor that anchors the whole dish. No extra cooking needed—just chop and stir.
• Balanced texture: Bread soaks up the egg mixture and turns custardy inside while the top gets golden and lightly crisp.
• Make-ahead friendly: Assemble it the night before to save time.The rest lets flavors mingle and guarantees even baking.
• Flexible ingredients: Any sturdy bread, most cheeses, and whatever veggies you have work well here. It’s hard to mess up.
• Feeds a crowd: One casserole pan delivers a complete breakfast with protein, dairy, and vegetables in each slice.

What You’ll Need

• 4 cups cubed day-old bread (sourdough, French, or whole wheat)
• 2 cups cooked ham, diced
• 1 cup shredded sharp cheddar (or a mix with Swiss or Monterey Jack)
• 8 large eggs
• 2 cups milk (whole or 2%; use 1 1/2 cups milk + 1/2 cup cream for richer texture)
• 1 cup vegetables, chopped (such as bell pepper, onion, spinach, or mushrooms)
• 2 tablespoons butter or olive oil (for sautéing vegetables and greasing the dish)
• 1 teaspoon Dijon mustard (optional but recommended for flavor depth)
• 1/2 teaspoon garlic powder
• 1/2 teaspoon onion powder
• 1/2 teaspoon dried thyme or Italian seasoning
• 1/2 teaspoon kosher salt
• 1/2 teaspoon black pepper
• 2–3 tablespoons chopped fresh herbs (optional: parsley or chives)

How to Make It

1. Prep the pan: Grease a 9×13-inch baking dish with butter or oil. Preheat your oven to 350°F (175°C) if baking right away.
2. Toast the bread (optional but helpful): If your bread is very soft, spread the cubes on a sheet pan and toast at 300°F for 8–10 minutes to dry them slightly.This helps the casserole set.
3. Sauté the veggies: Warm a skillet over medium heat with butter or oil. Cook onions and peppers 3–4 minutes until softened. If using mushrooms, cook until their moisture evaporates.Stir in spinach last and wilt briefly. Let cool slightly.
4. Whisk the custard: In a large bowl, whisk eggs, milk, Dijon, garlic powder, onion powder, thyme, salt, and pepper until smooth.
5. Layer the base: Add bread cubes to the baking dish. Scatter ham and sautéed vegetables over the top.Sprinkle most of the cheese evenly.
6. Add the custard: Pour the egg mixture over everything, pressing down gently so the bread absorbs the liquid. Top with the remaining cheese.
7. Rest time: Let it sit 10–15 minutes at room temperature, or cover and refrigerate overnight for the best texture.
8. Bake: If chilled, uncover and bake 45–55 minutes at 350°F, until the center is set and the top is golden. If baking right away, start checking at 40 minutes.A knife inserted near the center should come out clean.
9. Finish and serve: Rest 10 minutes before slicing. Sprinkle with fresh herbs and serve warm.

Storage Instructions

• Refrigerate: Cool completely, then cover and refrigerate for up to 4 days. Reheat slices in a 300°F oven for 10–15 minutes or microwave gently.
• Freeze: Wrap individual portions tightly and freeze up to 2 months.Thaw in the fridge, then reheat in the oven for best texture.
• Make-ahead: Assemble up to 24 hours in advance. Keep covered in the fridge. Add 5–10 minutes to the baking time if very cold.

Why This is Good for You

• High-protein breakfast: Eggs and ham offer sustained energy, helping you feel satisfied longer.
• Built-in vegetables: Peppers, onions, spinach, or mushrooms add fiber, vitamins, and color without extra pans.
• Portion control: Baking in a casserole makes it easy to serve measured slices and avoid overeating.
• Balanced macros: Protein, carbs from bread, and fat from cheese create a filling, well-rounded meal.

Common Mistakes to Avoid

• Using very soft, fresh bread: It can turn mushy.Day-old or lightly toasted bread holds up better.
• Skipping the veggie sauté: Raw veggies release water while baking and make the casserole watery.
• Overbaking: This can dry out the eggs. Pull it when the center is just set and the top is lightly browned.
• Underseasoning: Ham is salty, but the eggs and bread need flavor. Don’t skip the mustard, herbs, and spices.
• Cutting too soon: Let it rest 10 minutes so it sets and slices cleanly.

Alternatives

• Bread swaps: Try brioche for a richer casserole, rye for a savory twist, or gluten-free bread if needed.
• Cheese options: Swiss, Gruyère, pepper jack, or feta each add a distinct flavor.Mix for depth.
• Veggie variations: Broccoli florets, roasted zucchini, caramelized onions, or chopped tomatoes (well-drained) work well.
• Dairy-free: Use an unsweetened plant milk and a dairy-free cheese. Add an extra egg for structure if needed.
• No-ham version: Use cooked sausage, bacon, or a vegetarian option like sautéed mushrooms and extra spinach.
• Low-carb: Swap bread for small cauliflower florets or sautéed shredded cabbage; bake until set, knowing the texture is less custardy.

FAQ

Can I use fresh bread?

Yes, but it’s better to dry it out first. Cut it into cubes and toast briefly so it can soak up the custard without getting soggy.

Do I have to refrigerate it overnight?

No.

A 10–15 minute rest is enough in a pinch. Overnight resting gives a more even texture and richer flavor, but it’s optional.

How do I know it’s done?

The center should be set, not jiggly, and the top should be golden. A knife inserted near the middle should come out clean, and an instant-read thermometer should read about 165°F.

What if my casserole is watery?

It’s often from raw or watery veggies.

Make sure to sauté them and drain excess moisture. Also check that you used sturdy bread and baked until set.

Can I halve the recipe?

Yes. Use an 8×8-inch dish, reduce the ingredients by half, and start checking doneness around 30–35 minutes.

What can I serve with it?

Fresh fruit, a simple green salad, or roasted potatoes pair well.

A spoonful of salsa or hot sauce brightens each slice.

Can I add more eggs for extra protein?

You can add 1–2 more eggs, but increase milk slightly to keep the custard tender. Watch baking time and doneness cues.

Is pre-shredded cheese okay?

It works, but freshly shredded melts more smoothly. If using bagged cheese, choose a good-quality brand.

In Conclusion

This Leftover Ham Breakfast Casserole is a forgiving, flavorful way to turn scraps into a shared meal.

It rewards a little prep with a golden top, a tender center, and balanced, savory bites. Customize it with the vegetables and cheese you have, and make it ahead to keep mornings calm. One pan, easy cleanup, and plenty of comfort—exactly what breakfast should be.