Zucchini gratin is the perfect side dish for summer. Sauteed zucchini in a cheesy, creamy sauce is topped with a crunchy breadcrumb topping and baked until golden brown.
With summertime comes the abundance of fresh zucchini. We love to use it in sweet recipes like sourdough zucchini bread and zucchini cake with cream cheese frosting, and savory ones like zucchini lasagna, zucchini frittata, and stuffed zucchini boats.
Another favorite lately has been this simple zucchini gratin. It is simple to make, and yields the most cheesy, indulgent side. It’s perfect for pairing with roasted chicken or skillet pork chops with garlic and butter for a complete, crowd pleasing summer meal.
Why You’ll Love This Recipe
Perfect balance of textures – Tender zucchini, silky sauce, and a crisp, cheesy topping in every bite makes for the most flavorful recipe.
Great way to incorporate veggies – This kind of cheesy dish with a cream sauce is my favorite way to incorporate veggies for even the pickiest eaters.
Simple ingredients – This recipe is made with simple clean ingredients that you can feel good about!
Ingredients
Zucchini – This is a great way to use up this summer vegetable that is overflowing from the garden or the farmers market at this time of year.
Gruyere – I prefer to use fresh grated cheese rather than pre-packaged. This allows it to incorporate and melt more smoothly.
Bread crumbs – I love using homemade bread crumbs in this recipe. They are a great use for stale sourdough bread!
A full ingredient list with exact amounts can be found in the recipe card below.
How to Make Zucchini Gratin
Step 1: In a large skillet, melt the butter over medium heat. Add the sliced onion and cook for 5–7 minutes, until softened. Stir in the garlic and zucchini and cook for another 5 minutes, stirring occasionally.
Step 2: Season with nutmeg, salt, and pepper, then sprinkle in the flour and stir well to coat the vegetables.
Step 3: Pour in the milk and cream, followed by the lemon zest. Cook over medium-low heat for 3–4 minutes, stirring frequently, until the mixture thickens slightly. Taste and adjust seasoning if needed.
Step 4: Transfer the mixture to a greased casserole dish.
Step 5: In a small bowl, combine the Gruyere and breadcrumbs. Sprinkle evenly over the zucchini mixture, then dot the top with small pieces of butter.
Step 6: Bake for 20 minutes, until golden and bubbling. Serve warm.
Tips
- Slice zucchini evenly. Keeping the rounds similar in thickness helps them cook at the same rate so you don’t end up with some mushy and some firm pieces.
- This cheesy casserole pairs with almost any main course. It’s delicious alongside roast chicken, steak, pork, salmon, or baked ham.
- Allow the zucchini gratin to rest for a few minutes before serving to let the sauce set up.
Recipe FAQs
Due to the high water content of the zucchini, it is important to sauté it first for best results. This eliminates the excess moisture and avoids a watery dish.
While I wouldn’t recommend baking the entire dish ahead of time, you can make the process quicker by prepping the individual components early. Slice the vegetables, make the sauce, and prep your shredded cheese. You can then assemble the dish quickly and bake when needed.
There is no need to peel the zucchini! Leaving the skin on helps it to hold its shape when baking, and adds a beautiful color.
More Delicious Recipes from the Farmhouse
- Sheet Pan Gnocchi With Chicken And Vegetables
- The Best Homemade Baked Beans Recipe
- Easy And Delicious Beef Taco Skillet
- Mediterranean Sheet Pan Chicken And Vegetables
- Easy Homemade Refried Beans Recipe
If you try this recipe and love it, I would love it if you could come back and give it 5 stars! Tag me on Instagram @farmhouseonboone.
Cheesy Zucchini Gratin Recipe
Equipment
Ingredients
- 3 tablespoons butter
- 1 large yellow onion, sliced
- 1 clove garlic, minced
- 4 medium zucchini, cut into 1/4″ thick slices
- ¼ teaspoon ground nutmeg
- ½ teaspoon salt
- ⅛ teaspoon pepper
- 2 tablespoons flour
- 1 cup heavy cream, 10%
- ½ cup milk
- 1 teaspoon lemon zest
- 1 ½ cup Gruyere cheese, grated
- 1 cup bread crumbs
- 1 tablespoon butter, for topping before baking
Instructions
- Preheat the oven to 400 degrees Fahrenheit. Grease a large casserole dish, at least 2.5 quart capacity, and set aside.
- In a large skillet, melt the butter over medium heat. Add the sliced onion and cook for 5–7 minutes, until softened. Stir in the garlic and zucchini and cook for another 5 minutes, stirring occasionally.
- Season with nutmeg, salt, and pepper, then sprinkle in the flour and stir well to coat the vegetables.
- Pour in the milk and cream, followed by the lemon zest. Cook over medium-low heat for 3–4 minutes, stirring frequently, until the mixture thickens slightly. Taste and adjust seasoning if needed.
- Transfer the mixture to casserole dish.
- In a small bowl, combine the Gruyere and breadcrumbs. Sprinkle evenly over the zucchini mixture, then dot the top with small pieces of butter.
- Bake for 20 minutes, until golden and bubbling. Serve warm.
Notes
- Slice zucchini evenly. Keeping the rounds similar in thickness helps them cook at the same rate so you don’t end up with some mushy and some firm pieces.
- This cheesy casserole pairs with almost any main course. It’s delicious alongside roast chicken, steak, pork, salmon, or baked ham.
- Allow the zucchini gratin to rest for a few minutes before serving to let the sauce set up.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
