Name: Baked Zucchini Spinach and Feta Casserole Recipe
Prep time: 20 min
Cook time: 35 min
Total time: 55 min
Ingredients: 3 medium zucchini, thinly sliced into half moons; 4 cups fresh spinach, packed and roughly chopped; 1 small yellow onion, finely diced; 3 cloves garlic, minced; 2 tablespoons fresh parsley, chopped; 1 tablespoon fresh dill, chopped; 1 cup feta cheese, crumbled; 1 cup shredded mozzarella cheese; 1 cup grated Parmesan cheese, divided; 3 large eggs; 1 cup whole milk or half and half; 2 tablespoons olive oil, divided; 2 tablespoons butter, divided, plus extra for greasing the dish; 1 cup panko breadcrumbs; 1 teaspoon dried oregano; 1 teaspoon dried basil; 1 teaspoon kosher salt, plus more to taste; 1/2 teaspoon black pepper; 1/4 teaspoon red pepper flakes; 1 cup cooked quinoa or rice; 1/2 cup chopped sun dried tomatoes, drained

Baked Zucchini Spinach and Feta Casserole Recipe layers tender zucchini, garlicky spinach, and salty feta into a cozy, cheesy bake that tastes fresh yet comforting at the same time. It works perfectly for busy weeknights or casual brunch and takes about 55 minutes from start to finish. I tested versions of this casserole so many times that my neighbors started “checking in” right around dinnertime.

Why Make This Baked Zucchini Spinach and Feta Casserole Recipe at Home

This casserole packs in a lot of vegetables while still tasting rich and cheesy, so even picky eaters usually go back for seconds. You get Mediterranean flavor, a satisfying texture, and a lighter feel than a heavy pasta bake.

You also control the salt, the oil, and the cheese quality at home, which makes a big difference in the final flavor. Leftovers reheat beautifully, so you cook once and eat twice without any complaints from the table.

“This Baked Zucchini Spinach and Feta Casserole Recipe tastes like a cheesy Greek-inspired hug in a pan and disappears every time I serve it. ★★★★★”

Ingredients You Need

Fresh produce

3 medium zucchini, thinly sliced into half moons
- Choose firm zucchini with shiny skin and no soft spots for the best texture.
4 packed cups fresh spinach, roughly chopped
- Baby spinach wilts quickly and tastes mild, which works great here.
1 small yellow onion, finely diced
3 cloves garlic, minced
2 tablespoons fresh parsley, chopped
1 tablespoon fresh dill, chopped
- Dried dill works in a pinch: use 1 teaspoon dried instead.

Dairy and eggs

1 cup crumbled feta cheese
- I like sheep’s milk feta in brine; it tastes tangier and creamier than pre-crumbled.
1 cup shredded mozzarella cheese
- Low moisture, part skim melts nicely without turning greasy.
1 cup grated Parmesan cheese, divided
- Use half in the mixture and half on top for a golden crust.
3 large eggs
1 cup whole milk or half and half
- Whole milk keeps things lighter, half and half gives a richer custard.

Pantry items and seasonings

2 tablespoons olive oil
2 tablespoons butter, plus extra for greasing the dish
1 cup panko breadcrumbs
- Regular breadcrumbs also work, but panko gives a crunchier topping.
1 teaspoon dried oregano
1 teaspoon dried basil
1 teaspoon kosher salt, plus more to taste
½ teaspoon black pepper
¼ teaspoon red pepper flakes
- Optional, but they add a gentle kick that balances the richness.

Optional add ins

1 cup cooked quinoa or rice
- This turns the casserole into a more filling main dish.
½ cup chopped sun dried tomatoes, drained
- They add a sweet, tangy punch that pairs nicely with feta.

Equipment

9 by 13 inch baking dish
Large skillet
Medium mixing bowl
Whisk
Cutting board and sharp knife
Colander or clean kitchen towel to drain zucchini
Measuring cups and spoons

Tips & Mistakes

Salt the zucchini slices and let them sit 10 to 15 minutes, then pat dry, so the casserole does not turn watery.
Slice zucchini evenly so they cook at the same rate and keep a pleasant bite.
Sauté the onion until it turns lightly golden to build sweetness instead of leaving it sharp and raw tasting.
Let the spinach cook just until it wilts so it stays bright and does not turn mushy.
Taste the spinach and feta mixture before adding extra salt since feta already brings a lot of saltiness.
Use brined feta instead of dry crumbles to get a creamy, melty texture instead of chalky bits.
Grease the baking dish well so the cheesy edges release easily and you do not lose the best browned parts.
Do not overbake; pull the casserole when the center feels set and the top looks golden so it stays moist.
Let the casserole rest 10 to 15 minutes after baking so it slices cleanly and does not fall apart.
Cool leftovers completely before covering and chilling so condensation does not make the topping soggy.

How to Make Baked Zucchini Spinach and Feta Casserole Recipe

Step 1: Prep the zucchini

Slice the zucchini into thin half moons, about ⅛ to ¼ inch thick. Place the slices in a colander, sprinkle with 1 teaspoon salt, and toss to coat. Let them sit over the sink for 10 to 15 minutes so they release extra moisture, then pat them very dry with a clean towel.

Step 2: Cook the aromatics and spinach

Heat 1 tablespoon olive oil and 1 tablespoon butter in a large skillet over medium heat. Add the diced onion and cook 5 to 7 minutes until it turns soft and lightly golden. Stir in the garlic and cook 30 seconds until fragrant.

Add the chopped spinach in batches, stirring as it wilts. Season with a pinch of salt and pepper and cook 2 to 3 minutes until all the spinach wilts and most liquid cooks off. Turn off the heat and let the mixture cool slightly.

Step 3: Mix the cheesy filling

In a medium bowl whisk the eggs until smooth. Add the milk or half and half and whisk again. Stir in the feta, half of the Parmesan, half of the mozzarella, oregano, basil, red pepper flakes, parsley, and dill.

Fold the cooled spinach and onion mixture into the egg and cheese mixture. Taste a small spoonful and adjust salt and pepper if needed. The mixture should taste well seasoned and slightly salty since the zucchini will mellow it.

Step 4: Assemble the casserole

Heat the oven to 375°F and grease a 9 by 13 inch baking dish with butter or olive oil. Spread half of the zucchini slices in an even layer in the dish. Spoon half of the spinach and feta mixture over the zucchini and spread it gently.

Repeat with the remaining zucchini and the rest of the spinach mixture. Sprinkle the remaining mozzarella and half of the remaining Parmesan over the top. If you use cooked quinoa or rice, scatter it between the zucchini layers before you add the spinach mixture.

Step 5: Add the crunchy topping

In a small bowl mix the panko breadcrumbs, remaining Parmesan, and 1 tablespoon olive oil plus 1 tablespoon melted butter. Stir until the crumbs look evenly coated and slightly clumpy. Sprinkle this mixture evenly over the top of the casserole.

This topping will turn golden and crisp in the oven and give a nice contrast to the soft vegetables. If you like extra herbs, add a pinch of dried oregano or basil into the crumbs.

Step 6: Bake

Place the casserole on the middle rack of the oven. Bake 30 to 35 minutes until the top looks golden brown and the edges bubble. If the top browns too quickly, tent the dish loosely with foil for the last 10 minutes.

Check the center by inserting a knife; it should come out mostly clean and the middle should feel set, not liquid. Remove the casserole from the oven and let it rest 10 to 15 minutes before slicing.

Step 7: Slice and serve

Use a sharp knife to cut the casserole into squares. Use a spatula to lift out each piece so the layers stay intact. Sprinkle extra fresh herbs on top if you like a fresh pop of color and flavor.

Serve warm as a main dish or side. Enjoy the mix of creamy feta, tender zucchini, and crunchy topping while it still feels hot and bubbly.

Variations I've Tried

I swapped half the zucchini for thinly sliced yellow squash and liked the extra sweetness and color. I also tried mixing in cooked quinoa, which turned the casserole into a complete vegetarian main that kept everyone full.

Sometimes I stir in sun dried tomatoes and a handful of chopped olives for a stronger Mediterranean vibe. I also tested a lighter version with reduced fat feta and milk; it still tasted good, but the full fat cheeses gave a creamier texture and better browning.

If you avoid gluten, you can use gluten free panko or skip the crumbs and top with extra Parmesan and mozzarella. I also tried baking the casserole in individual ramekins, which worked nicely for portion control and made the edges extra crispy.

How to Serve Baked Zucchini Spinach and Feta Casserole Recipe

Serve this Baked Zucchini Spinach and Feta Casserole Recipe warm with a simple green salad and some crusty bread or warm pita on the side. It pairs nicely with tomato cucumber salad, roasted potatoes, or a bowl of vegetable soup. I also like it as a brunch dish next to scrambled eggs or a fruit salad. If you pack lunches, cut cooled squares and tuck them into containers with carrot sticks and hummus for an easy meal.

How to store

Fridge: Let the casserole cool completely, then cover the dish tightly or transfer slices to airtight containers and refrigerate up to 4 days.
Freezer: Wrap individual portions in plastic wrap, then place them in a freezer bag or container and freeze up to 2 months.
Reheat in oven: Place a portion in an oven safe dish, cover loosely with foil, and warm at 350°F for 15 to 20 minutes until hot in the center.
Reheat in microwave: Heat a slice on a microwave safe plate in 30 to 45 second bursts until hot, then let it sit 1 minute so the heat distributes evenly.