Preheat the oven to 450 degrees F.
Slice the zucchini and eggplant into thin planks lengthwise. Spray the eggplant and zucchini evenly on both sides with the cooking spray, and season with salt and pepper. Roast until tender and brown, about 20 minutes. Cool to handle.
Lower the oven temperature to 375 degrees F.
In a bowl, combine the ricotta, 1 cup of the Parm, all but a few tablespoons of the mint and parsley, egg yolks, garlic, chiles, a few grates of nutmeg and some salt and pepper. Spoon the stuffing onto each plank of eggplant or zucchini and roll up. Arrange the rolls in a baking dish and top with a few pieces of torn basil, then cover evenly with passata or tomato sauce.
Melt the butter in a small skillet, remove from the heat and toss with the panko, remaining Parm and remaining parsley and mint. For a make-ahead meal, store the breadcrumb mix in an airtight container and the roll ups in the fridge or freezer. Scatter the topping over the top of the dish. Bake from room temperature at 375 degrees F, until golden and bubbly.