Zucchini, Tomato & Black Olive Gratin: A Taste of the Mediterranean Sun

The aroma of late summer gardens always brings me back to my grandmother’s kitchen in Provence. I can almost smell the sun-drenched tomatoes, the earthy zucchini, and the briny olives that filled her rustic dishes. This Zucchini, Tomato & Black Olive Gratin perfectly captures that same essence – a celebration of simple ingredients transformed into a deeply flavorful and comforting bake. It’s a dish that reminds me of family, sunshine, and the pure joy of sharing good food.

Recipe Overview

• Prep Time: 20 minutes
• Cook Time: 25 minutes
• Total Time: 45 minutes
• Servings: 4-6
• Dietary Type: Vegetarian

Ingredients

• 2 medium onions, peeled and sliced
• 4 ounces extra virgin olive oil, divided
• 2 cloves garlic, minced
• ½ teaspoon thyme
• ½ teaspoon salt
• ½ teaspoon pepper
• ½ teaspoon chili flakes (optional)
• 6 ounces black olives, pitted and roughly chopped
• 3 medium zucchini, sliced
• 1 tablespoon basil, chopped
• 6 medium tomatoes, sliced
• 2 roasted red peppers, cut into wide strips
• 4 ounces breadcrumbs
• 4 ounces Parmesan cheese, grated
• 1 tablespoon parsley, chopped

Equipment Needed

• 8×8 inch casserole dish
• Large skillet
• Large bowl
• Measuring cups and spoons

Instructions

1. Preheat your oven to 375°F (190°C).

2. In a large skillet, heat 2 ounces of extra virgin olive oil over medium-high heat. Add the sliced onions and sauté for about 5 minutes, stirring occasionally to prevent burning.

3. Add the minced garlic, thyme, chili flakes (if using), salt, and pepper to the skillet with the onions. Continue cooking, stirring frequently, until the onions are golden brown and semi-soft, approximately 5 more minutes. The onions should be fragrant and starting to caramelize.

4. Remove the skillet from the heat and allow the onion mixture to cool slightly. Once cooled, stir in the roughly chopped black olives. Set aside.

5. In a large bowl, toss the sliced zucchini with the chopped basil and the remaining 2 ounces of extra virgin olive oil. Ensure the zucchini slices are evenly coated with the oil and basil.

6. Spread the onion and olive mixture evenly in the bottom of the 8×8 inch casserole dish. This layer will form the base of your gratin.

7. Begin layering the zucchini and tomato slices (alternating rows) on top of the onion mixture in the casserole dish. Interperse strips of roasted red peppers throughout the layers. Arrange the slices in a slightly overlapping fashion to ensure even cooking and a beautiful presentation.

8. Season each layer with a pinch of salt and pepper to taste. This step is crucial for bringing out the natural flavors of the vegetables.

9. In a separate bowl, mix together the breadcrumbs, grated Parmesan cheese, and chopped parsley. This mixture will create a delicious and crispy topping for the gratin.

10. Sprinkle the breadcrumb mixture evenly over the top of the vegetables in the casserole dish. Ensure that all the vegetables are covered for a golden-brown crust.

11. Bake in the preheated 375°F (190°C) oven for 25 minutes, or until the vegetables are tender and the topping is golden brown and crispy. A fork should easily pierce the zucchini and tomatoes when they are done. If the topping starts to brown too quickly, you can loosely tent the dish with foil for the last 10 minutes of baking.

12. Remove the gratin from the oven and let it cool slightly before serving. This will allow the flavors to meld together and the gratin to set.

Expert Tips & Tricks

• Roasting the red peppers yourself will add a deeper, smokier flavor to the gratin. Simply roast them under the broiler until the skin is blackened, then place them in a bowl covered with plastic wrap to steam. The skins will then easily peel off.
• For a richer flavor, try using sun-dried tomatoes in oil instead of fresh tomatoes. Be sure to drain the sun-dried tomatoes well before adding them to the gratin.
• If you don’t have fresh basil, you can use dried basil, but use half the amount (½ tablespoon). Fresh herbs always provide a brighter flavor, but dried herbs will still work in a pinch.
• To prevent the gratin from becoming too watery, you can salt the zucchini and tomatoes before layering them in the dish. This will draw out some of the excess moisture. Let them sit for about 30 minutes, then pat them dry with paper towels.
• Make-ahead Tip: Assemble the gratin ahead of time and store it in the refrigerator (unbaked) for up to 24 hours. Add the breadcrumb topping just before baking. This is a great way to save time when entertaining.

Serving & Storage Suggestions

This Zucchini, Tomato & Black Olive Gratin can be served warm or at room temperature. It makes a wonderful side dish to grilled meats or fish, or it can be enjoyed as a vegetarian main course. Garnish with a sprig of fresh basil or a drizzle of olive oil for an elegant presentation.

Leftovers can be stored in an airtight container in the refrigerator for up to 3 days. Reheat in the oven at 350°F (175°C) until warmed through. You can also reheat individual portions in the microwave. Freezing is not recommended, as the vegetables can become mushy upon thawing.

Nutritional Information

Nutrient	Amount per Serving	% Daily Value
Calories	617 kcal	N/A
Calories from Fat	388 g	63%
Total Fat	43.2 g	66%
Saturated Fat	9.9 g	49%
Cholesterol	24.9 mg	8%
Sodium	1329.6 mg	55%
Total Carbohydrate	42.7 g	14%
Dietary Fiber	7.4 g	29%
Sugars	11.8 g	N/A
Protein	19.1 g	38%

Variations & Substitutions

• Dairy-Free: Omit the Parmesan cheese or substitute it with a vegan Parmesan alternative. Nutritional yeast can also add a cheesy flavor.
• Gluten-Free: Use gluten-free breadcrumbs.
• Spicy: Add a pinch more of chili flakes or a dash of cayenne pepper to the onion mixture.
• Herby: Experiment with different herbs like oregano, rosemary, or marjoram in addition to or instead of thyme and basil.
• Cheese Variation: Try using mozzarella or provolone for a cheesier gratin.

FAQs (Frequently Asked Questions)

Q: Can I use yellow squash instead of zucchini?
A: Absolutely! Yellow squash is a great substitute and will provide a similar flavor and texture.

Q: What can I use if I don’t have roasted red peppers?
A: You can use jarred roasted red peppers, or simply omit them. A small amount of red bell pepper, thinly sliced, can also be used.

Q: Can I make this gratin in a different size dish?
A: Yes, but you may need to adjust the baking time. A larger dish will require less baking time, while a smaller dish may require more.

Q: Can I add other vegetables to this gratin?
A: Certainly! Eggplant, mushrooms, or bell peppers would all be delicious additions.

Q: Is it necessary to use Parmesan cheese?
A: While Parmesan cheese adds a lovely nutty flavor, you can substitute it with another hard cheese like Pecorino Romano, or even omit it for a dairy-free version.

Final Thoughts

This Zucchini, Tomato & Black Olive Gratin is more than just a recipe; it’s an invitation to savor the flavors of summer and create lasting memories in your own kitchen. I encourage you to give it a try, adapt it to your own tastes, and share it with the people you love. Whether you serve it as a side dish or a vegetarian main course, I hope it brings you as much joy as it brings me. Bon appétit!