Summer squash and zucchini gratin is the perfect summer side dish. This recipe is full of colorful and delicious vegetables that will either compliment the main dishes or be a main dish itself.
The main ingredients are squash and zucchini, of course, but it is also layered with shallots and garlic and then topped with a parmesan and panko crust. This dish is delicious and super easy to make making it a perfect dish for the summer.
What is a Gratin?
Gratin is simply a dish that has a browned topping. It is usually made in a shorter baking dish usually with a vegetable of sorts. You can top it with breadcrumbs, cheese or a combination of both. When you bake this layered dish, you’ll see the browned topping which is the “gratin.” You are probably familiar with potato gratin, which is one of my favorites, but gratins are made with all sorts of vegetables!

How do you make a Summer Gratin?
First, you’ll do a little stovetop cooking to ensure that the vegetables are tender. You’ll cook the squash, zucchini, garlic, shallots and salt and pepper until tender.

Next, you’ll add in some heavy cream and cook that until well mixed before adding a little parmesan and panko. Then, you’ll place it in the prepared baking dish and top with some more panko and parmesan before baking for about 10 minutes.

What do you serve with Summer Gratin?
You can serve this gratin as a main dish or a side dish. It is the perfect summer side dish and here are some dishes this gratin complements:
- Finger Lickin’ Apple Cider Grilled Ribs
- Air Fryer Buffalo Chicken Potato Skins
- Bacon Wrapped Cheesy Stuffed Chicken
Can I Prepare this in advance?
If you have time a little earlier in the day, you can prepare this and store in the refrigerator until it’s time to bake. One caveat is that I’d wait to add the parmesan and panko until you’re ready to bake. If you can, though, I’d prepare the ingredients and wait to combine until you’re ready to bake so that the ingredients don’t get soggy.

Summer Squash and Zucchini Gratin
Summer Squash & Zucchini Gratin is the perfect Summer Side Dish. It is colorful, and super delicious!
Ingredients
- 2 zucchini, cut into small chunks
- 2 squash, cut into small chunks
- 2 tablespoons butter
- 2 shallots, minced
- 1/2 red onion, diced
- Salt & pepper to taste
- 1 tablespoon garlic, minced
- ½ cup heavy whipping cream
- 1 cup panko crumbs, divided in half
- ½ cup parmesan cheese, divided in half
Instructions
- Preheat oven to 450 degrees
- In a skillet, cook onions, squash, zucchini, shallots, and salt & pepper in the butter until tender
- Add in garlic and cook 1 minute
- Stir in the cream and cook until thickened
- Remove from heat and stir in ½ the panko crumbs and parmesan cheese
- Spoon into 13x9 baking dish prepared with nonstick spray
- Sprinkle remaining panko and parmesan over the top
- Bake until golden brown and bubbly - about 10 minutes
Serve & enjoy!
Nutrition Information:
Yield:
10Serving Size:
1Amount Per Serving: Calories: 148Total Fat: 9gSaturated Fat: 5gTrans Fat: 0gUnsaturated Fat: 3gCholesterol: 24mgSodium: 223mgCarbohydrates: 13gFiber: 2gSugar: 3gProtein: 4g
This N That with Olivia, occasionally offers nutritional information for recipes contained on this site. This information is provided as a courtesy and is an estimate only. This information comes from online calculators. Although thisnthatwitholivia.com attempts to provide accurate nutritional information, these figures are only estimates.
Maryann D.
Sunday 26th of December 2021
My daughter would love this recipe, Summer Squash and Zucchini Gratin. She is a big fan of zucchini.
Kari B
Wednesday 14th of April 2021
This is such a great recipe idea!
Dana Rodriguez
Wednesday 14th of April 2021
I love squash. This llooks delicious!
Amy D
Wednesday 14th of April 2021
I love these veggies and always looking for new ways to prepare them. This looks delicious. I will pin it and look forward to trying it soon.