Zucchini & Yellow Squash Gratin Bliss

Introduction

When the garden overflows with vibrant zucchini and golden yellow squash, it’s time for a dish that celebrates these sunny vegetables in all their glory. Enter the Zucchini and Yellow Squash Gratin—a light, cheesy, and utterly satisfying dish that’s perfect for warm weather meals. This recipe pays homage to traditional French cuisine, where simple, fresh ingredients are elevated through careful layering, herbs, and a golden finish of bubbling cheese.

Growing up in a southern Italian home where my grandmother tended to her summer garden with pride, I watched her turn zucchini into endless meals—stews, fritters, and oven bakes. Inspired by her rustic methods and with a touch of French Provençal flair, I’ve developed this gratin to be lighter, gluten-free, and adaptable to a modern kitchen without sacrificing that old-world charm.

Whether you’re preparing a weekend brunch or need a fresh side dish for grilled meats, this Zucchini and Yellow Squash Gratin will become a go-to summer favorite.

Why You’ll Love This Gratin

• Seasonal freshness: Highlights the best of summer produce.

• Versatile: Great as a main or side dish.

• Low-carb and gluten-free: No breadcrumbs or flour needed.

• Simple ingredients: Just vegetables, cheese, herbs, and cream.

• Make-ahead friendly: Perfect for prepping a day in advance.

Ingredients

• 2 medium zucchinis, thinly sliced

• 2 medium yellow squash, thinly sliced

• 1 small onion, thinly sliced

• 2 cloves garlic, minced

• 1 cup shredded Gruyère or Swiss cheese

• 1/4 cup grated Parmesan cheese

• 1/2 cup heavy cream or half-and-half

• 1 tablespoon olive oil

• 1 teaspoon dried thyme or herbes de Provence

• Salt and freshly ground black pepper to taste

• Fresh basil or parsley for garnish (optional)

Instructions

Step 1: Preheat and Prepare

Preheat your oven to 375°F (190°C). Grease a 9×9-inch baking dish or gratin dish with olive oil or butter. Set aside.

Step 2: Slice Vegetables

Using a mandoline or sharp knife, thinly slice the zucchini and yellow squash into even rounds. Thin slices help the dish bake evenly and develop a delicate, layered texture.

Step 3: Sauté Onions and Garlic

In a pan over medium heat, warm olive oil and sauté the onions until soft and golden, about 8 minutes. Add garlic and cook for another 30 seconds, stirring frequently. Set aside to cool.

Step 4: Layer the Gratin

Spread half the sautéed onions at the base of the baking dish. Arrange zucchini and yellow squash slices in an overlapping pattern (alternating colors), creating beautiful concentric circles or rows. Sprinkle with salt, pepper, and dried herbs. Add the remaining onions on top and pour cream evenly over the layers.

Step 5: Add Cheese and Bake

Top with Gruyère and Parmesan. Bake uncovered for 35–40 minutes, or until the top is golden and bubbling and the squash is tender. If needed, broil for the last 2–3 minutes for extra browning.

Step 6: Rest and Serve

Let the gratin rest for 10 minutes before serving. This allows it to set and makes slicing easier. Garnish with chopped fresh herbs if desired.

Nutrition Highlights

Each serving is naturally low in carbohydrates and rich in flavor, calcium, and fiber. Here’s an approximate breakdown per serving:

• Calories: 240

• Protein: 10g

• Fat: 18g

• Carbs: 10g

• Fiber: 2g

• Sodium: 330mg

• Calcium: 25% Daily Value

Make-Ahead and Storage

• Refrigerate: Store leftovers in an airtight container for up to 3 days.

• Reheat: Warm in the oven at 350°F or microwave in 1-minute intervals.

• Freeze: This dish can be frozen after baking. Wrap tightly and store for up to one month. Reheat directly from frozen at 375°F for 25–30 minutes.

Recipe Notes and Variations

• Substitute half the cream with Greek yogurt for a tangy twist.

• Add thinly sliced tomatoes or eggplant to make it a full Provençal vegetable tian.

• Swap cheeses with sharp cheddar, fontina, or even goat cheese.

• Add breadcrumbs or crushed pork rinds if you want a crisp topping (optional).

What to Serve with Zucchini & Yellow Squash Gratin

This dish pairs beautifully with:

• Grilled chicken or salmon

• Roasted new potatoes or cauliflower mash

• A glass of chilled white wine or sparkling lemonade

• A green salad with lemon vinaigrette

Common Questions

Can I make this gratin dairy-free?
Yes. Use a plant-based cream (like cashew cream) and vegan cheese. Make sure they melt well and don’t separate at high heat.

Can I use only zucchini or only yellow squash?
Absolutely. You can double the quantity of one if you don’t have both on hand. The visual contrast of both adds beauty, but flavor-wise, they are interchangeable.

How thin should I slice the squash?
About 1/8 inch is ideal. This ensures even baking and a melt-in-your-mouth texture.

Zucchini & Yellow Squash Gratin Bliss

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• Author: Helen Bittner
• Total Time: 55 minutes
• Yield: 4 servings 1x
• Diet: Gluten Free

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Description

This Zucchini and Yellow Squash Gratin is a light yet indulgent dish featuring layers of summer squash baked in a creamy cheese sauce. With the perfect golden crust and a subtle blend of herbs, this recipe is inspired by rustic French gratins, making it an ideal side for grilled meats or a satisfying vegetarian main. It’s naturally gluten-free, low in carbs, and full of rich seasonal flavor.

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Ingredients

Scale 1x2x3x

• 2 medium zucchinis, thinly sliced

• 2 medium yellow squash, thinly sliced

• 1 small onion, thinly sliced

• 2 garlic cloves, minced

• 1 cup shredded Gruyère or Swiss cheese

• 1/4 cup grated Parmesan cheese

• 1/2 cup heavy cream or half-and-half

• 1 tablespoon olive oil

• 1 teaspoon dried thyme or herbes de Provence

• Salt and black pepper to taste

• Fresh basil or parsley for garnish (optional)

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Instructions

• Preheat oven to 375°F (190°C). Grease a 9×9-inch baking or gratin dish with olive oil.

• Thinly slice zucchini and yellow squash to about 1/8 inch thick. Set aside.

• In a pan over medium heat, sauté the onion in olive oil until soft, about 8 minutes. Add garlic and cook for another 30 seconds. Remove from heat.

• Layer half of the onion mixture in the baking dish. Arrange zucchini and yellow squash in overlapping rows or spirals, alternating colors.

• Sprinkle with salt, pepper, and herbs. Add remaining onion on top.

• Pour cream evenly over the top. Sprinkle with shredded Gruyère and Parmesan.

• Bake uncovered for 35–40 minutes, or until golden and bubbling. Broil for 2–3 minutes if needed.

• Rest for 10 minutes before slicing. Garnish with fresh herbs if desired.

Notes

• Use a mandoline for thin, even squash slices.

• Add tomato slices or eggplant for a Mediterranean twist.

• Substitute cream with full-fat coconut milk for a dairy-free version.

• Store leftovers in the fridge up to 3 days. Reheat at 350°F or microwave.

• Prep Time: 15 minutes
• Cook Time: 40 minutes
• Category: Side Dish, Main
• Method: Baked
• Cuisine: French

Nutrition

• Serving Size: 1/4 of dish
• Calories: 240
• Sugar: 4g
• Sodium: 330mg
• Fat: 18g
• Saturated Fat: 9g
• Unsaturated Fat: 8g
• Trans Fat: 0g
• Carbohydrates: 10g
• Fiber: 2g
• Protein: 10g
• Cholesterol: 55mg

Keywords: Zucchini and Yellow Squash Gratin, summer gratin, cheesy squash bake, low-carb vegetable bake