This Zucchini Au Gratin is a warm and comforting dish made with tender slices of zucchini, creamy spinach-cheddar filling, and a golden, cheesy crust. With layers of flavor from garlic, onion, herbs, and melty cheese, it’s the perfect side dish for any cozy dinner — or even as a light main course.
Why You Will Love This Recipe
- A rich and flavorful way to enjoy zucchini
- Uses pantry staples and fresh vegetables
- Can be made gluten-free
- A beautiful, crowd-pleasing dish
- The perfect balance of creamy and cheesy
Zucchini Au Gratin – Creamy, Cheesy, and Comforting with a Gourmet Twist
Zucchini is one of those humble vegetables that often gets overlooked, but when prepared right, it can completely transform a meal. This Zucchini Au Gratin is a perfect example. With just a bit of love — think blanching, sautéing, and layering — this dish becomes something truly crave-worthy.
The secret to great zucchini casseroles? Managing moisture. Zucchini contains a surprising amount of water, and unless you remove some of it before baking, you’ll end up with a soggy, soupy mess. But with a quick blanch and ice bath, followed by a gentle salt sprinkle, this recipe takes that extra step to ensure perfect texture.
While it sounds fancy (au gratin does have a certain ring to it), this dish is actually very easy to make. The base layer is sliced zucchini, lightly blanched to preserve its bite. Then comes a creamy, savory mixture of sautéed onion and garlic, cheddar, spinach, milk, and a few warming spices. It’s rich without being too heavy.
You’ll pour this luscious mixture over the zucchini and finish the dish with a layer of fontina and cheddar, some red pepper flakes for kick, and buttery cracker crumbs that turn beautifully golden in the oven.
The result? A bubbling, golden brown, cheesy casserole with just the right amount of creamy goodness. Every bite delivers subtle spice, gooey cheese, and tender zucchini layered together with just enough crunch from the topping.
It’s perfect as a side for roast chicken, grilled steak, or fish — but it’s hearty enough to stand alone with a green salad on the side. Vegetarian, satisfying, and absolutely irresistible.
This dish also makes great use of late summer zucchini when gardens and farmers markets are overflowing. It’s simple enough for a weeknight, but pretty enough for a dinner party.
Even kids who claim not to like zucchini will be swayed by the creamy filling and golden cheese crust.
You can prep it ahead and pop it in the oven before dinner, or reheat leftovers the next day — it holds up well and the flavors only deepen.
This is how you turn a humble veggie into a gourmet-worthy centerpiece.
Servings
Serves: 4–6
Time
Prep Time: 25 minutes
Cook Time: 20–25 minutes
Total Time: 45–50 minutes
Ingredients
- 1 large or extra-large zucchini, sliced into 1/4-inch discs
- 1/2 cup minced yellow onion
- 1 large clove garlic, minced
- 1 tsp olive oil (or butter)
- 1/4 cup milk
- 1/2 cup sharp cheddar cheese, freshly grated
- 1/8 tsp paprika
- 1/8 tsp garlic powder
- Pinch of nutmeg (optional)
- Pinch of allspice
- Pinch of salt
- 1 large egg
- 1/2 cup fontina cheese, freshly grated
- 1/4 cup sharp cheddar cheese, freshly grated (extra for topping)
- 2–3 tbsp chopped fresh spinach
- 1/8 tsp red pepper flakes
- 3–4 buttery crackers, crushed
Instructions
- Preheat oven to 350°F (175°C). Fill a bowl with ice water and set aside.
- Bring a pot of water to a boil. Blanch zucchini slices for 1 minute, then plunge into the ice bath.
- Drain and pat dry with paper towels. Sprinkle lightly with salt and let sit to draw out moisture.
- In the same pot, sauté onion and garlic in olive oil until soft.
- Add milk, 1/2 cup cheddar, spinach, paprika, garlic powder, nutmeg, allspice, and a pinch of salt. Stir well and remove from heat.
- Let cool slightly, then stir in egg.
- Pat zucchini slices dry again. Layer in a shallow baking dish.
- Pour the creamy mixture over zucchini.
- Top with fontina, 1/4 cup extra cheddar, red pepper flakes, and crushed crackers.
- Cover loosely with foil and bake for 15–18 minutes until bubbly.
- Remove foil and broil for 3–5 minutes until golden. Watch closely to avoid burning.
Tips
- Use a mandoline for evenly sliced zucchini.
- Substitute breadcrumbs or gluten-free crackers for topping.
- Add extra spinach or herbs for more greens.
- Make ahead and reheat — it stores well!
