Zucchini Tomato Gratin: The Riviera Summer Bake with a Gruyère Crust

Instructions:

1. Preheat oven to 190°C (375°F). Lightly grease the baking dish with olive oil. Rub the inside of the dish thoroughly with the cut side of the halved garlic clove, then discard the clove.
2. Using a mandoline or a sharp knife, slice the zucchini and tomatoes uniformly thin (aim for 2-3mm / ⅛ inch thick).
3. Place the zucchini slices in a large bowl. Toss with ½ teaspoon of salt and set aside for 10 minutes. This critical step draws out excess moisture.
4. Gently blot the zucchini slices dry with kitchen paper. Combine the dried zucchini and tomato slices, tossing lightly with the 1 tablespoon of olive oil, thyme, pepper, and the remaining ½ teaspoon of salt.
5. Starting at the outside edge, arrange the zucchini and tomato slices, slightly overlapping them in concentric circles or rows, working your way towards the centre of the dish.
6. In a small bowl, combine the melted butter, Panko breadcrumbs, grated Gruyère, minced garlic (if using), and chopped parsley. Mix until the Panko is evenly coated.
7. Sprinkle the Panko mixture evenly over the exposed vegetables.
8. Cover the dish tightly with foil or parchment paper. Place in the preheated oven and bake for 30 minutes. This allows the vegetables to steam tenderly.
9. Remove the foil. Increase the oven temperature slightly to 200°C (400°F) if needed, and bake for an additional 15-20 minutes, or until the topping is deeply golden brown and bubbling.
10. Remove the gratin from the oven and allow it to rest for at least 10 minutes before serving. This allows the gratin to set and prevents it from collapsing.