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
Scale
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.
