A twist on the summer vegetable stew traditionally from Nice, this version offers stacks of eggplant, zucchini, and potato slices baked in a fragrant tomato and fennel sauce for an attractive presentation.
Slice the eggplant and zucchini into ¼-inch-thick slices with a knife or mandoline. Lay the eggplant slices on paper towels, sprinkle with kosher salt, and let sit for 30 minutes to remove any bitterness.
Rinse off the salt and press dry with a clean kitchen towel.
Meanwhile, put the potatoes with the skin on in a large pot of salted water and parboil for 5 minutes. Let cool, and then peel and cut into ¼-inch-thick slices.
Preheat the oven to 325ºF.
Heat the oil in a large skillet over medium heat. Add the diced onion, cored and diced fennel, and garlic and cook, stirring, until the onions and fennel are soft, about 5 minutes. Add the thyme and crushed red pepper and cook for 30 seconds. Add the tomatoes, bring to a simmer, and cook, stirring occasionally, until slightly thickened, about 15 minutes. Season with Maldon salt and black pepper.
Spread the sauce on the bottom of an 11-by-7-inch baking dish. Make a shingled stack with 1 slice of the eggplant, zucchini, and potato. Arrange on top of the sauce, rounded sides up. Season with Maldon salt and black pepper as you go. Repeat to fill the dish. Drizzle with oil.
Bake until the vegetables are beginning to soften and brown, about 45 minutes. Cover with foil and continue to bake until the vegetables are completely tender, about 45 more minutes. Sprinkle with grated pecorino if desired.