If you have been on the lookout for a comforting yet fresh dish to brighten your dinner table, this Zucchini Au Gratin Recipe is exactly what you need. It’s a luscious, creamy bake that highlights tender zucchini with a golden, cheesy crust that is simply irresistible. The beautiful medley of tender squash, savory garlic, and Parmesan cheese creates a harmony of flavors and textures that’ll have everyone asking for seconds and holding onto this recipe for years to come! This is comfort food with a refreshing twist, perfect for anyone who wants a vibrant dish that feels both hearty and wholesome.
Ingredients You’ll Need
This Zucchini Au Gratin Recipe calls for a handful of simple ingredients that work together to create layers of flavor and texture. Each one plays a crucial role in balancing creaminess, earthiness, and just the right amount of richness.
- Zucchini (2-2½ pounds): Choose fresh yellow or green zucchini for a lovely color contrast and tender bite.
- Uncooked long-grain white rice (1 cup): This adds a subtle texture that soaks up the richness without becoming mushy.
- Diced onions (1 cup): They provide a sweet, aromatic foundation that enhances the overall flavor.
- Olive oil (3 tablespoons + 2 tablespoons): Used for sautéing and added richness, olive oil brings out the natural flavors.
- Minced garlic (2 large cloves): Garlic gives that irresistible, savory punch that elevates the dish.
- Flour (3 tablespoons): This is essential for thickening the sauce and achieving the perfect creamy consistency.
- Whole milk (1¼ cups): A rich base for the sauce, creating that smooth, velvety texture we all love.
- Reserved zucchini juice (1 cup): Adds moisture and an intensified zucchini flavor into the sauce.
- Grated Parmesan cheese (1 cup, divided): The star cheese that melts to a golden crust, offering a salty, nutty finish.
- Kosher salt and freshly ground black pepper: To season and bring all the ingredients together perfectly.
How to Make Zucchini Au Gratin Recipe
Step 1: Prep Your Casserole Dish and Oven
Start by spraying a large 8-10 cup casserole dish with nonstick cooking spray to ensure your cheesy gratin doesn’t stick and cleans up easily. Preheat your oven to a warm 400°F and place the oven rack in the upper third position. This heat setup helps the top cheese layer achieve that perfect golden crisp.
Step 2: Prepare the Zucchini and Rice
Wash and slice the zucchini thinly—whether yellow, green, or a delightful blend—to create a nice visual texture. Rinse the uncooked long-grain rice thoroughly under cold water to remove excess starch for fluffier grains. Set both aside while you start on the flavorful base.
Step 3: Cook Onions and Garlic
Warm 3 tablespoons of olive oil in a medium pan over medium heat. Add the diced onions and sauté until they become translucent and sweet, about 5-7 minutes. Stir in the minced garlic and cook for another minute until fragrant without browning. This aromatic base is what makes the sauce so comforting.
Step 4: Make the Creamy Sauce
Sprinkle in the flour to the onion and garlic mixture and cook for 2 minutes, stirring continuously. This helps remove the raw flour taste and begins to thicken your sauce. Slowly whisk in the whole milk and reserved zucchini juice, then bring to a simmer. Keep stirring until smooth and thickened, which usually takes about 4-5 minutes.
Step 5: Add Cheese and Seasonings
Remove the sauce from heat and stir in half of the grated Parmesan cheese. Season with kosher salt and freshly ground black pepper to taste. This cheesy sauce is the heart of the dish, creamy with a beautiful umami bite from the Parmesan.
Step 6: Assemble Your Zucchini Au Gratin
Layer the sliced zucchini evenly in your prepared casserole dish. Pour the creamy Parmesan sauce over the zucchini, spreading gently with a spatula to coat everything. Sprinkle the uncooked rice evenly on top, then finish with the remaining Parmesan cheese. This layering ensures each bite has a wonderful balance of vegetables, sauce, and that signature crisp topping.
Step 7: Bake Until Golden and Bubbly
Place the casserole in the oven and bake uncovered for about 60 minutes. You’ll know it’s done when the top is golden brown, bubbly, and the rice is tender. Let it rest for about 10 minutes before serving to let the flavors meld and the casserole set up a bit for easier portioning.
How to Serve Zucchini Au Gratin Recipe
Garnishes
A sprinkle of fresh chopped herbs like parsley or chives adds a vibrant pop of color and a fresh herbal note that complements the rich, cheesy layers perfectly. For an extra touch, a few shavings of Parmesan on top right before serving always impresses guests.
Side Dishes
This Zucchini Au Gratin Recipe is hearty on its own but pairs beautifully with a crisp green salad dressed with lemon vinaigrette or roasted chicken for a complete meal. For a vegetarian twist, serve alongside quinoa or a rustic bread to soak up every last bit of the delicious sauce.
Creative Ways to Present
For a stunning presentation, try layering the ingredients in individual ramekins for single servings or use colorful heirloom zucchini for a striking visual. Another fun idea is to mix in other seasonal vegetables like thinly sliced carrots or summer squash to add more color and texture.
Make Ahead and Storage
Storing Leftovers
Once cooled, cover your Zucchini Au Gratin tightly with plastic wrap or transfer to an airtight container and store in the refrigerator for up to 4 days. The flavors actually develop even more overnight, making leftovers a delightful treat.
Freezing
You can freeze leftover Zucchini Au Gratin, but keep in mind that the texture of zucchini and rice may soften slightly. Store in a freezer-safe container for up to 2 months. Thaw overnight in the fridge before reheating for best results.
Reheating
Reheat your leftovers in a 350°F oven until warmed through and bubbly, usually about 20 minutes. To revive some crispiness on top, you can gently broil it for a minute or two—just keep an eye on it to avoid burning.
FAQs
Can I use frozen zucchini for this recipe?
Fresh zucchini is best here because it holds its texture better during baking. If you use frozen zucchini, make sure to thaw and drain it thoroughly to avoid excess moisture that could water down the sauce.
Is it possible to make this recipe dairy-free?
Yes! You can substitute whole milk with a creamy plant-based milk like oat or almond, and swap Parmesan for dairy-free cheese alternatives. Keep in mind this will slightly change the flavor profile, but it will still be delicious.
Can I prepare this dish vegan?
To make a vegan Zucchini Au Gratin Recipe, replace butter or olive oil with plant-based oils, use a vegan cheese substitute, and choose a non-dairy milk. Nutritional yeast can add that cheesy flavor to the sauce.
What can I substitute for long-grain rice?
If you want to skip rice or don’t have any on hand, small pasta like orzo or even finely chopped cauliflower rice can work as alternatives, though the texture will be a bit different.
How do I prevent the dish from becoming watery?
Make sure to slice the zucchini thinly and evenly and avoid using frozen zucchini unless well-drained. Also, the reserved zucchini juice is balanced with flour and cheese, which helps control excess moisture in the gratin.
Final Thoughts
This Zucchini Au Gratin Recipe is truly a celebration of fresh ingredients elevated into a dish that feels like a special occasion. It’s straightforward to make, wonderfully flavorful, and comforting in all the right ways. Dive into creating this beautiful gratin for your next dinner and watch it become an instant favorite that friends and family will cherish as much as you do.
Print
Zucchini Au Gratin Recipe
- Prep Time: 20 minutes
- Cook Time: 60 minutes
- Total Time: 80 minutes
- Yield: 8 to 9 servings
- Category: Casserole
- Method: Baking
- Cuisine: American
Description
This Zucchini Au Gratin recipe is a comforting and flavorful baked dish featuring tender zucchini slices layered with a creamy garlic Parmesan sauce and a crispy golden top. Perfect as a side or a light main course, it combines the freshness of zucchini with the richness of cheese and garlic, creating a satisfying and elegant casserole that serves eight to nine people.
Ingredients
Zucchini and Vegetables
- 2–2½ pounds zucchini (yellow squash or a blend of yellow and green zucchini)
- 1 cup diced onions
- 2 large cloves garlic (minced)
Grains
- 1 cup uncooked long-grain white rice (NOT Minute Rice)
Liquids and Oils
- 3 tablespoons olive oil (for sauce)
- 1¼ cups whole milk
- 1 cup reserved zucchini juice
- 2 tablespoons olive oil (for drizzling)
Cheese and Seasoning
- 1 cup grated Parmesan cheese (divided)
- 3 tablespoons flour
- Kosher salt and freshly ground black pepper (to taste)
Instructions
- Preheat and Prepare Casserole: Spray a large (8-10 cup) casserole dish with nonstick cooking spray. Heat the oven to 400°F and place the oven rack in the upper third position.
- Prepare Zucchini: Cut the zucchini into slices or preferred shape. Place the zucchini in a large bowl and salt it lightly to draw out excess moisture. Let it sit for 10-15 minutes, then drain and reserve the juice separately.
- Cook Rice: Rinse the long-grain white rice thoroughly and cook it according to package instructions until tender but not mushy. Set aside.
- Sauté Onions and Garlic: In a large skillet, heat 3 tablespoons of olive oil over medium heat. Add the diced onions and cook until translucent, about 5 minutes. Add the minced garlic and cook for another 1-2 minutes until fragrant.
- Make the Sauce: Sprinkle 3 tablespoons of flour over the onions and garlic in the skillet, stirring constantly to form a roux. Gradually whisk in the whole milk and reserved zucchini juice, continuing to whisk until the mixture thickens into a creamy sauce. Season with kosher salt and freshly ground black pepper to taste. Remove from heat and stir in half of the grated Parmesan cheese.
- Combine Ingredients: In a large mixing bowl, combine the drained zucchini slices, cooked rice, and the creamy cheese sauce. Toss gently to coat everything evenly.
- Assemble the Dish: Transfer the mixture into the prepared casserole dish. Sprinkle the remaining Parmesan cheese evenly on top. Drizzle 2 tablespoons of olive oil over the cheese layer to help it crisp during baking.
- Bake: Place the casserole dish in the preheated oven and bake uncovered for about 60 minutes, or until the top is golden brown and bubbling.
- Cool and Serve: Remove the dish from the oven and let it cool slightly before serving to allow the casserole to set. Enjoy warm as a delicious side or light main course.
Notes
- Use a blend of yellow and green zucchini for a colorful presentation and varied flavor.
- Reserving the zucchini juice for the sauce adds moisture and pure zucchini flavor.
- Long-grain white rice adds texture; do not substitute with instant or Minute Rice for best results.
- For a lighter version, substitute whole milk with 2% or use less cheese.
- This dish can be prepared a day ahead and refrigerated; reheat covered with foil to prevent drying out.
- Adjust seasoning according to taste before baking.
