Here’s a comforting and versatile zucchini casserole that showcases tender slices of zucchini baked in a creamy, cheesy custard until golden and bubbling. Bright summer squash, aromatic herbs, and a mix of cheeses create a rich texture that’s both homey and elegant. Ready in less than an hour, it’s great as a side for roasted meats or a vegetarian main with a salad.
Ingredients
– 4 medium zucchini, sliced 1/4-inch thick
– 1 medium onion, thinly sliced
– 2 cloves garlic, minced
– 1 cup shredded cheddar cheese
– 1/2 cup grated Parmesan
– 1 cup milk or half-and-half
– 2 large eggs
– 2 tablespoons olive oil
– 1/2 cup breadcrumbs (optional)
– 1 teaspoon salt
– 1/2 teaspoon black pepper
– 1 teaspoon dried thyme or 1 tablespoon fresh chopped
– 1/2 teaspoon paprika (optional)
Servings and Cooking Time
Serves: 4–6. Preparation time: 15 minutes. Cooking time: 30–35 minutes. Total time: about 45–50 minutes.
Nutritional Value
The following is approximate nutritional information for one serving (serving size: about 1/6 of the casserole):
– Calories: 280 kcal
– Protein: 12 g
– Fat: 18 g
– Carbohydrates: 16 g
– Fiber: 2 g
– Sodium: 520 mg
This nutritional breakdown is for one person per serving.
Step-by-Step Cooking Process
– Preheat oven to 375°F (190°C) and grease a 9×13-inch or similarly sized baking dish.
– Wash and dry zucchini; slice into even 1/4-inch rounds so they cook uniformly.
– Toss zucchini with olive oil, salt, pepper, and thyme in a large bowl to coat.
– Sauté sliced onion in a skillet over medium heat until soft and translucent, then add garlic and cook 1 minute.
– Spread half the zucchini in the prepared dish, then layer the sautéed onions over it.
– Sprinkle half the cheddar and a little Parmesan evenly over the first layer.
– Arrange the remaining zucchini slices on top in an even layer.
– Whisk eggs with milk, remaining salt and pepper, and paprika; pour mixture evenly over the layered zucchini.
– Top with remaining cheddar, Parmesan, and breadcrumbs if using for a crunchy finish.
– Bake uncovered 30–35 minutes until edges are bubbling and the top is golden brown; let rest 5–10 minutes before serving.
Alternative Ingredients
You can swap cheddar for Gruyère or mozzarella for a milder melt. Use Greek yogurt or sour cream mixed with a splash of milk instead of all milk/cream. Gluten-free breadcrumbs or almond flour work for topping. Fresh herbs like basil or dill change the flavor profile.
Serving and Pairings
Serve warm as a side with roasted chicken, grilled fish, or pork chops. For a vegetarian meal, pair with a crisp green salad, crusty bread, or a grain salad (quinoa or farro). A squeeze of lemon brightens the casserole.
Storage and Reheating
Store leftover zucchini casserole in an airtight container in the refrigerator for up to 3–4 days. To reheat, warm single portions in the microwave 1–2 minutes or reheat the whole dish in a 350°F (175°C) oven until heated through, about 15–20 minutes. This casserole freezes well for up to 2 months; thaw overnight in the fridge before reheating.
Cooking Mistakes
– Over-salting before baking — cheeses add salt, so taste first.
– Slicing zucchini unevenly — thin, even slices ensure consistent cooking.
– Skipping the rest time — cutting too soon makes it runny.
– Crowding the pan — overcrowded slices steam instead of roasting.
– Using very watery zucchini — pat slices dry to avoid sogginess.
– Relying solely on low-fat dairy — can make texture thin and watery.
Helpful Tips
– Salt zucchini slices briefly and drain excess moisture for a firmer bake.
– Use a mix of cheeses for both flavor and good melting properties.
– Let the casserole rest 10 minutes to set before slicing.
– Add a thin layer of breadcrumbs or panko for a crispy top.
– Stir in a tablespoon of Dijon for subtle depth.
– Try thinly sliced tomatoes layered for extra color and acidity.
FAQs
How do I prevent my zucchini casserole from becoming watery?
Drain excess moisture by salting sliced zucchini and letting it sit in a colander for 10–15 minutes, then press gently with paper towels. Lightly sautéing or roasting slices before assembling also removes water. Using less milk or adding a binder like extra egg helps the custard set firmer.
Can I make this casserole ahead of time?
Yes — assemble the casserole, cover, and refrigerate for up to 24 hours before baking. Allow it to sit at room temperature 20 minutes before placing in a preheated oven. Baking time may increase slightly if going straight from the fridge.
Is this zucchini casserole vegetarian or suitable for a low-carb diet?
This recipe is vegetarian if you use vegetarian-friendly cheeses. For lower carbs, reduce or omit breadcrumbs and use higher-fat dairy like cream and more cheese; it will still be relatively low in carbs but higher in fat.
Can I add other vegetables or proteins to the casserole?
Absolutely — thinly sliced eggplant, bell peppers, or cooked mushrooms layer well. For protein, fold in cooked crumbled sausage, shredded chicken, or canned tuna before baking to make it heartier.
How do I make the top extra golden and bubbly?
Sprinkle an extra layer of cheese and a light dusting of breadcrumbs during the last 10 minutes of baking or broil for 1–2 minutes, watching closely to avoid burning. Brushing breadcrumbs with a little olive oil helps crisp them.
What temperature and dish size work best for even cooking?
A 375°F (190°C) oven and a 9×13-inch or similar shallow casserole dish distribute heat well. Use an oven-safe dish with even depth so the custard sets evenly without overbaking edges.
Can I make this gluten-free?
Yes — omit breadcrumbs or use certified gluten-free breadcrumbs or ground nuts. Ensure any processed cheeses or seasonings used are labeled gluten-free to avoid cross-contamination.
Conclusion
Zucchini casserole is an easy, adaptable bake that turns simple summer squash into a creamy, cheesy favorite. With quick prep, flexible ingredients, and satisfying results, it’s perfect for weeknight dinners, potlucks, or as a make-ahead side that keeps well and reheats beautifully.
Zucchini Casserole
Ingredients
- 4 medium zucchini sliced 1/4-inch thick
- 1 medium onion thinly sliced
- 2 cloves garlic minced
- 1 cup shredded cheddar cheese
- 1/2 cup grated Parmesan
- 1 cup milk or half-and-half
- 2 large eggs
- 2 tablespoons olive oil
- 1/2 cup breadcrumbs optional
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1 teaspoon dried thyme or 1 tablespoon fresh chopped
- 1/2 teaspoon paprika optional
Instructions
- Preheat oven to 375°F (190°C) and grease a 9x13-inch or similar baking dish.
- Wash and dry zucchini; slice into even 1/4-inch rounds so they cook uniformly.
- Toss zucchini with olive oil, salt, pepper, and thyme in a large bowl to coat.
- Sauté sliced onion in a skillet over medium heat until soft and translucent, then add garlic and cook 1 minute.
- Spread half the zucchini in the prepared dish, then layer the sautéed onions over it.
- Sprinkle half the cheddar and a little Parmesan evenly over the first layer.
- Arrange the remaining zucchini slices on top in an even layer.
- Whisk eggs with milk, remaining salt and pepper, and paprika; pour mixture evenly over the layered zucchini.
- Top with remaining cheddar, Parmesan, and breadcrumbs if using for a crunchy finish.
- Bake uncovered 30–35 minutes until edges are bubbling and the top is golden brown; let rest 5–10 minutes before serving.
Nutrition
