A hearty, cheesy, veggie-packed baked casserole made with seasoned ground beef, zucchini, tomatoes, eggs, and plenty of melted cheese. The layers bake together into a firm, sliceable casserole with a beautifully golden, bubbly top. Similar ground-beef-and-zucchini casseroles commonly use zucchini, beef, eggs, tomato, and mozzarella/cheddar-style cheeses.
Ingredients
For the beef filling
- 1 lb (450 g) ground beef
- 2 medium zucchini, thinly sliced
- 1 small onion, finely chopped
- 2–3 cloves garlic, minced
- 1 cup diced tomatoes, drained
- 2 tbsp tomato paste
- 1 tbsp olive oil
- 1 tsp Italian seasoning
- 1 tsp paprika
- ½ tsp dried oregano
- ½ tsp salt, or to taste
- ½ tsp black pepper
- ¼ tsp red pepper flakes, optional
For the egg mixture
- 4 large eggs
- ½ cup milk or half-and-half
- ¼ cup grated Parmesan cheese
- ½ tsp Italian seasoning
- ¼ tsp salt
- ¼ tsp black pepper
For the cheesy topping
- 1½ cups shredded mozzarella
- ½ cup shredded cheddar
- ¼ cup Parmesan
- 2 tbsp chopped fresh parsley
Instructions
1. Prepare the zucchini
Preheat your oven to 375°F (190°C).
Slice the zucchini into thin rounds or half-moons. Sprinkle lightly with salt and let them sit for about 10 minutes.
Pat them thoroughly with paper towels.
Important: Zucchini contains a lot of water. Removing some moisture helps prevent a watery casserole and gives you cleaner slices.
2. Cook the ground beef
Heat olive oil in a large skillet over medium-high heat.
Add the chopped onion and cook for 3–4 minutes, until softened.
Add the garlic and cook for another 30 seconds.
Add the ground beef and cook for 6–8 minutes, breaking it apart with a wooden spoon until browned and fully cooked.
Drain excess grease if necessary.
3. Add the tomato mixture
Stir in:
- Diced tomatoes
- Tomato paste
- Italian seasoning
- Paprika
- Oregano
- Salt
- Black pepper
- Red pepper flakes, if using
Cook for another 4–5 minutes, allowing the mixture to thicken.
Remove from heat.
4. Prepare the egg mixture
In a large bowl, whisk together:
- 4 eggs
- Milk
- Parmesan
- Italian seasoning
- Salt
- Black pepper
Whisk until smooth.
5. Layer the casserole
Lightly grease a 9 × 9-inch or 8 × 11-inch baking dish.
Arrange a layer of zucchini slices on the bottom.
Add a portion of the cooked beef mixture.
Add another layer of zucchini.
Pour the egg mixture evenly over the casserole, allowing it to settle between the layers.
Add the remaining beef mixture.
6. Add the cheese
Sprinkle the mozzarella and cheddar evenly over the top.
Finish with Parmesan.
The cheese should completely cover most of the surface so it becomes beautifully golden and bubbly while baking.
7. Bake
Place the casserole in the preheated oven.
Bake uncovered for approximately 30–40 minutes, or until:
- The center is set
- The eggs are fully cooked
- The zucchini is tender
- The cheese is melted and bubbling
- The top is golden brown
If the cheese is browning too quickly, loosely cover the dish with foil.
8. Rest before slicing
Remove from the oven and allow it to rest for 10–15 minutes.
This is important because the egg mixture needs time to firm up. It also makes it much easier to cut the casserole into neat squares like the one shown in your picture.
Garnish with fresh parsley and serve warm.
Serving Suggestions
Serve this casserole with:
- Fresh green salad
- Cucumber and tomato salad
- Roasted broccoli
- Steamed vegetables
- Sliced avocado
- Fresh tomato salad
- A small piece of crusty bread
For a lower-carb meal, serve it with a large green salad instead of bread.
Recipe Information
Prep Time: 20 minutes
Cook Time: 35–40 minutes
Resting Time: 10–15 minutes
Total Time: About 1 hour 10 minutes
Servings: 6
Approximate Nutrition Information
Estimated per serving; exact nutrition will vary depending on the fat percentage of the beef, amount/type of cheese, and milk used.
- Calories: ~430–470 kcal
- Protein: ~30–33 g
- Carbohydrates: ~10–13 g
- Fat: ~29–32 g
- Saturated Fat: ~12–15 g
- Fiber: ~2–3 g
- Sugar: ~5–7 g
- Sodium: ~650–800 mg
- Calcium: ~300–350 mg
- Iron: ~3–4 mg
Similar published beef-and-zucchini casseroles report roughly 25–31 g protein per serving, depending on the ingredients and portion size.
Nutrition Notes
- High in protein: Beef, eggs, and cheese make this quite filling.
- Good source of vegetables: Zucchini and tomatoes add vitamins, minerals, and fiber.
- Lower in carbohydrates: Since there is no pasta, rice, or potato, it can fit many lower-carb meal patterns.
- Calcium-rich: Mozzarella, cheddar, and Parmesan contribute calcium.
- To reduce calories: Use lean ground beef and part-skim mozzarella.
- To increase protein: Use lean beef and add a little cottage cheese to the egg mixture.
Easy Substitutions
Ground beef
You can substitute:
- Ground turkey
- Ground chicken
- Lean ground pork
Cheese
Instead of mozzarella, try:
- Provolone
- Monterey Jack
- Colby Jack
- Cheddar
- Italian cheese blend
Vegetables
You can add:
- Bell peppers
- Mushrooms
- Spinach
- Eggplant
- Broccoli
Dairy-free
Use your favorite dairy-free shredded cheese and an unsweetened dairy-free milk.
LONG Q&A
Q: Can I make this casserole ahead of time?
Yes. Assemble the casserole, cover it tightly, and refrigerate it for up to about 24 hours before baking. Because it starts cold, you may need a little additional baking time.
Q: Why is my zucchini casserole watery?
Zucchini releases a significant amount of water while cooking. Salting the sliced zucchini, waiting about 10 minutes, and patting it dry helps. Also make sure canned tomatoes are well drained.
Q: Can I use frozen zucchini?
Yes, but fresh zucchini is preferable. If using frozen zucchini, thaw it completely and squeeze out as much excess water as possible before adding it.
Q: Can I use ground turkey instead of beef?
Absolutely. Ground turkey makes a lighter version while still working very well with zucchini, tomato, herbs, and cheese.
Q: Can I make this low carb?
Yes. The recipe is already relatively low in carbohydrates because it doesn’t contain pasta, rice, or breadcrumbs. For an even lower-carb version, use unsweetened low-carb milk and check that your tomato products contain no added sugar.
Q: Can I make it without eggs?
Eggs help bind the casserole and give it the sliceable texture shown in the picture. You can experiment with an egg substitute, but the final texture will be softer.
Q: Can I add more vegetables?
Yes. Mushrooms, bell peppers, spinach, and eggplant work particularly well. Avoid adding too many watery vegetables unless you cook them first.
Q: Can I make this spicy?
Definitely. Add red pepper flakes, cayenne pepper, diced jalapeño, or a little hot sauce to the beef mixture.
Q: How do I get the cheese really golden?
Bake uncovered during the final portion of cooking. For an extra-golden top, place it under the broiler for 1–2 minutes, watching carefully so it doesn’t burn.
Q: Why should I let it rest before cutting?
Resting allows the egg and cheese mixture to firm up. If you cut it immediately, the layers can slide apart and release more liquid.
Q: Can I freeze it?
Yes. Cool completely, portion it, wrap tightly, and freeze. Thaw overnight in the refrigerator before reheating. Published zucchini-beef casserole recipes also use freezing successfully, particularly when the casserole is cooled and reheated gently.
Q: How long will leftovers last?
Store leftovers in an airtight container in the refrigerator for about 3–4 days.
Q: How should I reheat it?
Reheat individual portions in the microwave, or place the casserole in a 350°F (175°C) oven until heated through. Covering it loosely with foil helps prevent the cheese from becoming too dry.
Q: Can I use a different baking dish?
Yes. A 9-inch square dish works well for a thicker casserole, while a 9 × 13-inch dish will produce a thinner casserole and may require slightly less baking time.
Q: Is this good for meal prep?
Yes. Cut it into individual portions after cooling and refrigerate them in airtight containers. It’s convenient for breakfast, lunch, or dinner.
Q: What makes this recipe filling?
The combination of protein from beef and eggs, fat and protein from cheese, and volume/fiber from zucchini and tomatoes makes it a satisfying meal.
Q: Can I add breadcrumbs?
Yes, if you want a crispier topping. Sprinkle about ¼ cup seasoned breadcrumbs over the cheese before baking. This will increase the carbohydrate content.
Best Tip
Don’t skip squeezing/patting the zucchini dry. That’s the biggest trick for getting a thick, cheesy casserole that cuts into beautiful squares instead of becoming watery. Similar zucchini casseroles specifically recommend removing excess moisture before baking.
Perfect for: family dinner • meal prep • high-protein meals • low-carb dinners • cheesy comfort food • zucchini lovers