Summer Vegetable Gratin

This delicious and flavorful Summer Vegetable Gratin recipe is a delightful way to showcase the best of the season’s produce. Combining zucchini, summer squash, and ripe tomatoes, this gratin is topped with a rich breadcrumb mixture and Parmesan cheese, creating a satisfying and elegant dish. The key to success lies in properly preparing the vegetables to avoid excess moisture and achieving the perfect caramelization. This gratin makes for a perfect side dish or a light main course, serving four hungry diners.

SERVES 4

INGREDIENTS:

• 2 garlic cloves, minced
• 1 tablespoon minced fresh thyme
• 1 slice hearty white sandwich bread, torn into quarters
• 2 ounces Parmesan cheese, grated (1 cup)
• 2 shallots, minced
• ¼ cup chopped fresh basil
• 1 teaspoon salt (for salting vegetables)
• ½ teaspoon salt (for caramelized onions)
• ½ teaspoon salt (for sprinkling on tomatoes)
• ½ teaspoon pepper
• 4 tablespoons olive oil (divided)
• 2 zucchinis, sliced
• 2 summer squashes, sliced
• 4 ripe tomatoes, sliced

INSTRUCTIONS:

1. Toss the sliced zucchini and summer squash with 1 teaspoon of salt and let them drain in a colander for about 45 minutes, until they release at least 3 tablespoons of liquid. Pat them dry thoroughly with paper towels afterward to remove excess moisture.
2. Spread the tomato slices on a paper towel-lined baking sheet, sprinkle them with ½ teaspoon of salt, and let them stand for 30 minutes. Pat the tomatoes dry with paper towels.
3. In a 12-inch nonstick skillet, heat 1 tablespoon of olive oil over medium heat until shimmering. Add the onions and ½ teaspoon of salt, and cook them, stirring occasionally, until they soften and turn dark golden brown (about 20 to 25 minutes). Set the caramelized onions aside.
4. In a bowl, combine 3 tablespoons of olive oil, minced garlic, thyme, and ½ teaspoon of pepper. Set aside this garlic-oil mixture.
5. Process the sandwich bread in a food processor until finely ground, then combine it with 1 tablespoon of olive oil, grated Parmesan, and minced shallots in a separate bowl. Set aside the breadcrumb mixture.
6. Adjust the oven rack to the upper-middle position and preheat the oven to 400 degrees Fahrenheit (200 degrees Celsius). Grease a 3-quart gratin dish or a 13 by 9-inch baking dish with the remaining 1 tablespoon of olive oil.
7. Toss the drained zucchini and summer squash with half of the garlic-oil mixture and arrange them in the greased baking dish. Sprinkle the caramelized onions evenly over the vegetables, then layer the tomato slices on top, overlapping them slightly. Spoon the remaining garlic-oil mixture evenly over the tomatoes.
8. Bake the gratin in the preheated oven for 40 to 45 minutes or until the vegetables are tender, and the tomatoes start to brown at the edges.
9. Remove the baking dish from the oven and increase the oven temperature to 450 degrees Fahrenheit (230 degrees Celsius).
10. Sprinkle the breadcrumb mixture evenly over the top of the gratin and continue baking for an additional 5 to 10 minutes, until the gratin is bubbling, and the cheese is lightly browned.
11. Let the gratin cool for 10 minutes, then sprinkle chopped fresh basil over the top before serving.

TIPS:

• Choose High-Quality Vegetables: To ensure the best results, use fresh and high-quality zucchini, summer squash, and ripe tomatoes. Look for vegetables of roughly the same diameter to ensure even cooking.
• Salting and Draining Vegetables: Salting the zucchini and summer squash before assembly helps to draw out excess moisture, preventing the gratin from becoming watery. Make sure to drain them for at least 45 minutes and then pat them dry thoroughly with paper towels.
• Roasted Tomatoes: Let the tomatoes stand for 30 minutes after sprinkling with salt to help draw out excess moisture. Pat them dry before adding to the gratin. The exposure to more heat while layering them on top ensures they end up roasted and caramelized.
• Caramelized Onions: Take the time to caramelize the onions properly. Cooking them slowly over medium heat for about 20-25 minutes adds a sweet and rich flavor to the gratin.
• Breadcrumb Topping: The breadcrumb mixture, combined with Parmesan, shallots, and oil, creates an elegant and flavorful topping. Process the bread until finely ground for the perfect texture.
• Baking Time: Follow the baking times closely to achieve the right level of tenderness for the vegetables and the desired browned texture on top.

Enjoy this delightful Summer Vegetable Gratin as a side dish or a light main course, perfect for savoring the flavors of the season!