Introduction
When summer gardens overflow with fresh zucchini and yellow squash, it’s time to get creative in the kitchen. Zucchini Gratin with Yellow Squash is a delightful dish that combines the natural sweetness of these vibrant vegetables with a rich, creamy cheese sauce and a golden breadcrumb topping. Whether you’re hosting a family dinner, preparing for a potluck, or simply looking for a comforting meal on a busy weeknight, this dish has you covered.
Gratins, originating from French cuisine, are known for their rich flavors and crispy, caramelized toppings. This version brings together simplicity and sophistication. The blend of zucchini and yellow squash not only offers a balance of flavors but also creates a visually appealing dish with its green and yellow hues. Packed with nutrients like vitamins A and C, this recipe isn’t just tasty—it’s healthy too!
In this blog, we’ll cover everything you need to know to make the perfect Zucchini Gratin with Yellow Squash. From step-by-step instructions to variations, tips for storage, and common FAQs, you’ll have all the tools to create a masterpiece in your kitchen.
Ingredients
For the Vegetable Base:
- 2 medium zucchinis, thinly sliced
- 2 medium yellow squashes, thinly sliced
- 1 small onion, finely diced
- 2 cloves garlic, minced
- 2 tablespoons olive oil
- 1 teaspoon salt
- ½ teaspoon black pepper
- ½ teaspoon Italian seasoning
For the Creamy Sauce:
- 3 tablespoons butter
- 3 tablespoons all-purpose flour
- 1½ cups milk (whole or 2%)
- ½ cup heavy cream
- 1 cup shredded Gruyère or mozzarella cheese
- ½ cup grated Parmesan cheese
- 1 teaspoon Dijon mustard
- ¼ teaspoon nutmeg (optional for added depth of flavor)
For the Topping:
- 1 cup panko breadcrumbs
- 2 tablespoons butter, melted
- 2 tablespoons fresh parsley, chopped (optional for garnish)
Directions
Step 1: Prepare the Vegetables
- Preheat the Oven
Start by preheating your oven to 375°F (190°C). This ensures the gratin will bake evenly and develop a golden-brown crust. - Slice the Squash
Wash the zucchini and yellow squash thoroughly. Using a sharp knife or mandoline, slice them into uniform rounds about ¼-inch thick. Uniform slicing is key for even cooking. - Sauté the Vegetables
Heat olive oil in a large skillet over medium heat. Add the diced onion and sauté until it turns translucent, about 3–4 minutes. Next, add the minced garlic and cook for another 30 seconds until fragrant.
Toss in the sliced zucchini and yellow squash. Sprinkle with salt, pepper, and Italian seasoning. Sauté the vegetables for about 5 minutes, or until slightly softened. Remove from heat and set aside.
Step 2: Make the Creamy Cheese Sauce
- Prepare a Roux
In a medium saucepan, melt the butter over medium heat. Once melted, whisk in the all-purpose flour to form a roux. Cook the roux for 1–2 minutes, stirring constantly, to eliminate the raw flour taste. - Add Milk and Cream
Gradually whisk in the milk and heavy cream, pouring slowly to prevent lumps. Bring the mixture to a gentle simmer, stirring continuously until it thickens. - Incorporate Cheese and Flavorings
Remove the saucepan from heat and stir in Dijon mustard, nutmeg (if using), shredded Gruyère, and Parmesan cheese. Mix until the cheese is completely melted and the sauce is smooth. Set aside.
Step 3: Assemble the Gratin
- Prepare the Baking Dish
Lightly grease a 9×13-inch baking dish with butter or non-stick spray. - Layer the Vegetables
Spread the sautéed zucchini and yellow squash slices evenly in the baking dish. - Pour the Cheese Sauce
Carefully pour the prepared cheese sauce over the vegetables, ensuring they are fully coated. Use a spatula to spread the sauce evenly if needed. - Add the Topping
In a small bowl, combine the panko breadcrumbs with melted butter. Sprinkle this mixture evenly over the top of the gratin. This will create a crispy, golden-brown crust.
Step 4: Bake and Serve
- Bake
Place the assembled gratin in the preheated oven. Bake for 25–30 minutes, or until the top is golden brown and the cheese sauce is bubbling around the edges. - Broil for Extra Crispness
For a crispier topping, switch to the broiler setting for the last 2–3 minutes. Keep a close eye to avoid burning. - Garnish and Serve
Remove the gratin from the oven and let it cool slightly. Garnish with fresh parsley for a burst of color and flavor. Serve warm as a side dish or main course.
Servings and Timing
- Servings: 6
- Prep Time: 15 minutes
- Cook Time: 35 minutes
- Total Time: 50 minutes
Variations
1. Add Protein
Transform this gratin into a one-dish meal by adding shredded chicken, turkey, or crumbled sausage. Mix the protein into the sautéed vegetables before layering.
2. Herbal Enhancements
Enhance the flavor with herbs like thyme, rosemary, or basil. Sprinkle fresh herbs over the gratin before baking.
3. Cheese Swaps
Experiment with different cheeses for a unique flavor profile. Sharp cheddar, gouda, or fontina can be used in place of Gruyère or mozzarella.
4. Low-Carb Option
Replace panko breadcrumbs with crushed pork rinds or almond flour for a keto-friendly alternative.
5. Vegan Adaptation
To make the gratin vegan, use plant-based milk, vegan cheese, and substitute olive oil for butter. You can also thicken the sauce with cornstarch instead of a roux.
Storage and Reheating
Storage
- Refrigerator: Store leftovers in an airtight container for up to 3–4 days.
- Freezer: To freeze, let the gratin cool completely. Place it in a freezer-safe container and store for up to 2 months.
Reheating
- Oven: Reheat in a preheated 350°F oven for 15–20 minutes. Cover with foil to retain moisture, then uncover for the last few minutes to crisp up the topping.
- Microwave: For quick reheating, use the microwave. Heat individual portions for 2–3 minutes, though the topping may lose some of its crispness.
10 FAQs About Zucchini Gratin with Yellow Squash
1. Can I use other types of squash?
Yes! Pattypan squash or butternut squash can be excellent substitutes or additions.
2. What’s the best cheese for gratin?
Gruyère and Parmesan are traditional choices, but feel free to use your favorite melting cheese, like cheddar or gouda.
3. Can I make this dish ahead of time?
Absolutely! Assemble the gratin, cover tightly, and refrigerate for up to 24 hours. Bake it just before serving.
4. Is this recipe gluten-free?
To make it gluten-free, replace the flour with gluten-free all-purpose flour and use gluten-free breadcrumbs.
5. Do I need to peel the squash?
No. The skin is tender and provides additional nutrients and texture.
6. Can I add more vegetables?
Certainly! Sliced tomatoes, eggplant, or bell peppers are great additions.
7. What can I pair with this dish?
Serve this gratin with grilled chicken, baked salmon, or a crisp garden salad.
8. How do I prevent watery gratin?
Sauté the zucchini and squash beforehand to reduce moisture and drain any excess liquid.
9. Can I double the recipe?
Yes! Use a larger baking dish and adjust the cooking time slightly to ensure even baking.
10. Is nutmeg essential in the sauce?
No, but it adds a subtle depth of flavor that complements the creamy sauce.
Conclusion
Zucchini Gratin with Yellow Squash is more than just a recipe—it’s a celebration of seasonal produce and comforting flavors. The creamy sauce, cheesy layers, and crunchy topping make it a dish that’s both indulgent and wholesome. Whether you stick to the classic version or try one of the suggested variations, this gratin is bound to become a family favorite.
Pair it with your favorite entrée or enjoy it on its own. It’s easy to prepare, store, and reheat, making it perfect for any occasion. Try this recipe today, and savor the irresistible blend of textures and flavors!