I’ll always remember making my first crostata. It was from my friend Johanne Killeen’s cookbook Cucina Simpatica. Johanne and her late husband George Germon started Al Forno restaurant in Providence; 40 years later, it’s still one of my favorite places — and I just adore Johanne’s cookbook. Her apple crostata is both elegant and earthy, a flaky, buttery crust filled with sweet apples. It’s divine! Over the years, I’ve played around with lots of other sweet crostatas, like one with a raspberry-rhubarb filling (it’s in my book Cooking for Jeffrey), but I also love savory crostatas. I make this tomato and goat cheese version with the same flaky crust (minus the sugar), a layer of creamy goat cheese on the bottom and big slices of gorgeous heirloom tomatoes on top. The trick is to bake it on an upside-down sheet pan: Because there are no sides on the pan to block the heat, the tart browns more evenly. This crostata, served with a salad, is a perfect summer lunch!
For the pastry, place the flour and 1/2 teaspoon salt in the bowl of a food processor fitted with the steel blade and pulse to combine. Add the diced butter and toss carefully with your fingers to coat each piece of butter with flour. Pulse 12 to 15 times, until the butter is the size of peas. While pulsing, add the ice water all at once through the feed tube. Pulse to combine, stopping just before the dough forms a ball. Turn the dough out onto a well-floured board and form it into a disk. Wrap in plastic and refrigerate for one hour.
Meanwhile, preheat the oven to 450˚ F. Heat the 4 tablespoons butter in a large (12-inch) sauté pan over medium to medium-high heat. Add the leeks, thyme, 1 teaspoon salt and 1/2 teaspoon pepper and sauté for 8 minutes, until the leeks are tender and starting to brown. Set aside. Place the tomatoes on a plate, sprinkle them with salt and pepper and drizzle lightly with olive oil. Set aside.
On a floured board, roll the dough into an 11-inch circle, then place it on a sheet of parchment paper. Turn a sheet pan upside down and transfer the paper to the inverted pan. Spread the leeks on the pastry, leaving a 1 1/2-inch border. Crumble the goat cheese evenly on top. Arrange the tomatoes over the goat cheese, overlapping the slices because they will shrink. Turn the edges of the pastry up and over the tomatoes, crimping so they lie flat. Brush the pastry with the egg wash. Bake for 25 to 30 minutes, until the pastry is nicely browned. Allow to cool on the pan for 5 minutes, sprinkle lightly with the fresh herbs and salt, cut in wedges and serve warm.
Cut the tomatoes crosswise with a serrated knife. Use only the beautiful center slices.