Easy Homemade Garden Zucchini Casserole — A Healthy, Traditional Summer Favorite

Garden Zucchini Casserole has been my go-to for summer dinners for years, and the first bite always tastes like sunshine. This easy, homemade casserole is a traditional family-style dish that turns a garden full of zucchini into warm, comforting food — perfect for weeknight dinners, Sunday family meals, or a holiday side everyone will ask about.

🧂 Ingredients

• 2 tablespoons olive oil or 2 tablespoons butter (or a mix)
• 1 medium yellow onion, finely chopped (about 1 cup)
• 2 cloves garlic, minced
• 4 cups thinly sliced zucchini (about 3 medium zucchini)
• 1 cup halved cherry tomatoes (optional for color and brightness)
• 1 cup shredded cheddar cheese (or mozzarella for milder flavor)
• 1/2 cup grated Parmesan cheese
• 1/2 cup plain Greek yogurt or 1 cup cottage cheese (for creaminess)
• 1/2 cup breadcrumbs or panko (use gluten-free if needed)
• 2 large eggs, lightly beaten
• 2 teaspoons Dijon mustard or 1 teaspoon dried mustard (optional)
• 1 teaspoon dried oregano or Italian seasoning
• 1/2 teaspoon smoked paprika (or sweet paprika)
• Salt and freshly ground black pepper, to taste
• Fresh herbs for garnish: chopped parsley or basil
• Nonstick spray or a little extra oil for the baking dish

Optional add-ins:

• 1 cup cooked quinoa or cooked lentils (for extra protein)
• 1/2 cup crumbled feta for a tangy twist
• 1/4 cup sliced black olives or roasted red peppers

👩‍🍳 Directions

1. Preheat the oven to 375°F (190°C). Grease a 9×9-inch (or similar) baking dish with oil or nonstick spray.
2. Optional prep: If zucchinis are very watery, sprinkle sliced zucchini with 1 tsp salt, let sit 10–15 minutes, then gently squeeze out excess moisture with a clean towel. This keeps the casserole from getting soggy.
3. Heat olive oil or butter in a large skillet over medium heat. Add chopped onion and sauté 4–5 minutes until translucent.
4. Add minced garlic and cook 30 seconds until fragrant. Stir in sliced zucchini and cook 6–8 minutes until just tender but not mushy. If using cherry tomatoes, add them in the last 2 minutes.
5. Remove the skillet from heat and let veggies cool slightly (3–5 minutes). Transfer to a large mixing bowl.
6. To the bowl, add Greek yogurt or cottage cheese, beaten eggs, Dijon mustard, oregano, smoked paprika, salt, and pepper. Mix well. Stir in 3/4 cup of the shredded cheddar and 1/4 cup Parmesan. If using cooked quinoa or lentils, fold them in now.
7. Pour the mixture into the prepared baking dish. Sprinkle the top evenly with the remaining cheddar, Parmesan, and breadcrumbs. For extra crunch, toss breadcrumbs with a little melted butter before sprinkling.
8. Bake uncovered at 375°F (190°C) for 25–30 minutes until set and bubbling, and the top is golden brown. If the top browns too fast, tent loosely with foil for the last 10 minutes.
9. Let the casserole rest 10 minutes before slicing — this helps it set and be easier to serve. Garnish with fresh parsley or basil. Serve warm.

Cooking tips:

• If your zucchini variety is very large, remove seeds from the center and slice thinner.
• For a deeper golden top, broil for 1–2 minutes at the very end — watch closely to avoid burning.

💡 Tips & Variations

• Vegan: Use a plant-based yogurt, silken tofu blended until smooth, and vegan shredded cheese. Swap eggs for 2 tablespoons ground flaxseed mixed with 6 tablespoons water (let sit 5 minutes). Use nutritional yeast for a cheesy flavor.
• Low-carb / Keto: Replace breadcrumbs with 1/2 cup almond meal and use full-fat cheese and Greek yogurt or cream cheese. Skip tomatoes and quinoa.
• Gluten-free: Use certified gluten-free breadcrumbs or panko. Most other ingredients are naturally gluten-free.
• Higher-protein: Stir in 1 cup cooked, shredded chicken or 1 cup cooked lentils/beans. Cottage cheese or ricotta also boosts protein.
• Add a Mediterranean twist: Use feta, olives, oregano, and a squeeze of lemon before serving.
• Make-ahead: Assemble the casserole, cover, and refrigerate up to 24 hours. Add 5–10 minutes to baking time if chilled.
• Leftovers: Store in an airtight container in the fridge for up to 3–4 days. Reheat covered in a 350°F (175°C) oven for 10–15 minutes or microwave individual portions until warm.
• Freezing: Freeze baked casserole in an airtight container for up to 2 months. Thaw overnight in fridge and reheat in oven. For best texture, avoid freezing if using dairy-heavy or egg-based binders — it still works but can change texture slightly.
• Serving ideas: Serve as a main with a crisp green salad, or as a side with roasted chicken, grilled fish, or a simple steak. Great for potlucks — it transports well in a covered dish.

If you like kitchen gear, a nonstick baking dish, a good box grater, or a mandoline can make this even easier — I often link to my favorites as affiliate picks on the blog to help choose the best tools.

🩺 Health & Lifestyle Tie-in

Zucchini is low in calories and rich in vitamin C, potassium, and fiber — a great way to stretch your garden harvest into a nutrient-dense meal. Adding Greek yogurt, cottage cheese, or beans increases protein for fullness and muscle health. Choosing olive oil and moderate cheese keeps the dish heart-friendly. Eating simple, homemade meals like this regularly can support long-term wellness — and healthy habits now may help reduce future health costs. Small swaps (low-sodium options, extra veggies) keep it both delicious and mindful.

❤️ Conclusion

This Garden Zucchini Casserole is one of those comforting, forgiving recipes that feels like home no matter how you make it. It’s easy to adapt, healthy, and perfect for feeding a crowd or saving as weekday lunches. If you make this dish, let me know in the comments or tag me on social — I’d love to see your version and any creative twists you tried!

Happy cooking, and enjoy those garden zucchinis!

Garden Zucchini Casserole

This easy, homemade casserole transforms a garden full of zucchini into a comforting dish perfect for weeknight dinners or family gatherings.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 30 minutes mins

Total Time 45 minutes mins

Servings: 6 servings

Course: Main Course, Side Dish

Cuisine: American, Mediterranean

Calories: 350

Ingredients Method Notes

Ingredients

  

Main Ingredients

• 2 tablespoons olive oil or butter (or a mix)
• 1 medium yellow onion, finely chopped (about 1 cup)
• 2 cloves garlic, minced
• 4 cups thinly sliced zucchini (about 3 medium zucchini)
• 1 cup halved cherry tomatoes (optional) For color and brightness
• 1 cup shredded cheddar cheese (or mozzarella) For milder flavor
• 1/2 cup grated Parmesan cheese
• 1/2 cup plain Greek yogurt or cottage cheese For creaminess
• 1/2 cup breadcrumbs or panko Use gluten-free if needed
• 2 large eggs, lightly beaten
• 2 teaspoons Dijon mustard or 1 teaspoon dried mustard (optional)
• 1 teaspoon dried oregano or Italian seasoning
• 1/2 teaspoon smoked paprika (or sweet paprika)
• Salt and freshly ground black pepper, to taste
• Fresh herbs for garnish: chopped parsley or basil
• Nonstick spray or oil for the baking dish

Optional Add-Ins

• 1 cup cooked quinoa or cooked lentils For extra protein
• 1/2 cup crumbled feta For a tangy twist
• 1/4 cup sliced black olives or roasted red peppers

Method

 

Preparation

1. Preheat the oven to 375°F (190°C). Grease a 9x9-inch (or similar) baking dish with oil or nonstick spray.
2. Optional prep: If zucchinis are very watery, sprinkle sliced zucchini with 1 tsp salt, let sit 10–15 minutes, then gently squeeze out excess moisture with a clean towel.

Cooking

1. Heat olive oil or butter in a large skillet over medium heat. Add chopped onion and sauté 4–5 minutes until translucent.
2. Add minced garlic and cook for 30 seconds until fragrant. Stir in sliced zucchini and cook for 6–8 minutes until just tender but not mushy. If using cherry tomatoes, add them in the last 2 minutes.
3. Remove the skillet from heat and let veggies cool slightly (3–5 minutes). Transfer to a large mixing bowl.
4. To the bowl, add Greek yogurt or cottage cheese, beaten eggs, Dijon mustard, oregano, smoked paprika, salt, and pepper. Mix well. Stir in 3/4 cup of the shredded cheddar and 1/4 cup Parmesan. If using cooked quinoa or lentils, fold them in now.
5. Pour the mixture into the prepared baking dish. Sprinkle the top evenly with the remaining cheddar, Parmesan, and breadcrumbs. For extra crunch, toss breadcrumbs with a little melted butter before sprinkling.
6. Bake uncovered at 375°F (190°C) for 25–30 minutes until set and bubbling, and the top is golden brown. If the top browns too fast, tent loosely with foil for the last 10 minutes.
7. Let the casserole rest for 10 minutes before slicing. Garnish with fresh parsley or basil. Serve warm.

Notes

For a deeper golden top, broil for 1–2 minutes at the very end — watch closely to avoid burning. Store leftovers in an airtight container in the fridge for up to 3–4 days.