Ratatouille can take many forms.
There’s fancy: eggplant, tomatoes and zucchini artfully cut and arranged in a dish before baking – the kind of thing you don’t mind getting the china down for. And there’s simple: a potentially sloppy mix of long-stewed vegetables, liable to collapse in an oily heap on your everyday plates before being devoured.
The same can be said for ratatouille baked in a crust. It can be an elegant tart, a dainty quiche or, as in this case, a rustic pie that’s homely, but impossible to resist. Its golden crust shatters messily when you cut it. The custard filling could leak, escaping the pastry. The cheese may brown; the tomatoes on top may shrivel.
None of that matters when you taste it, each buttery, creamy, vegetable-filled bite flavored with herbs and olives, and covered in cheese.
This recipe is very loosely based on a Southern tomato pie. There’s a parbaked pie crust anchoring the vegetables, and a custard imbued with mayonnaise and cheese to bind them. But that’s where the similarities end.
Here, I skipped the raw tomatoes, substituting a mix of summer vegetables cooked in plenty of olive oil until velvety soft. I particularly like to roast them so they caramelize and release much of their moisture, which keeps the pastry from turning soggy. If you have leftover ratatouille or any kind of cooked vegetables – roasted, grilled, sautéed – in your fridge, you could use those instead. You'll need about three to four cups of cooked vegetables, enough to fill the crust by two-thirds.
If you are using your own cooked vegetables instead of roasting them as in the recipe, be sure to stir in plenty of herbs: basil, rosemary and thyme. These add a lot in terms of complexity, and keep the olives from taking over.
Now, about the mayonnaise. While it may seem like an odd match with ratatouille, it has an inherent tanginess that works well with the richness of the vegetables. I did try baking a version using crème fraîche to make it a little more French-seeming. But, to me, the result was insipid. Purists can make their own mayonnaise if anyone objects to using the stuff from the jar.
No matter how else you tweak it, make sure to bake the pie on the day of serving. This hot mess is its best, stunning self when it’s just that: just baked, a little warm from the oven and delightfully gooey.
Yield: 8 servings
Total time: 2 hours, plus cooling
For the crust
1 1/4 cups all-purpose flour
1/2 teaspoon kosher salt
1/2 teaspoon sugar
1/2cup unsalted butter (1 stick), cut into cubes, plus more for buttering foil
1/3 cup ice water, plus more if needed
For the filling
1 large eggplant (about 1 1/2 pounds), cut into 3/4-inch cubes
1/2 cup extra-virgin olive oil
5 garlic cloves, smashed and peeled
1 tablespoon rosemary leaves, chopped
1 tablespoon thyme leaves
Kosher salt, as needed
1 cup cherry tomatoes, cut in half
1 large white onion, sliced 1/4-inch thick
1 small zucchini or summer squash, cut into 3/4-inch cubes (about 7 ounces)
1 large egg
3/4 cup coarsely grated white cheddar or Gruyère
1/4 cup freshly grated Parmesan
1/3 cup mayonnaise
1/4 teaspoon black pepper, plus more as needed
1/2 cup basil leaves, chopped
1 small plum tomato, sliced 1/4-inch thick (optional)
1 tablespoon chopped Moroccan black olives (or other good black olives)
Make the dough: In a large bowl, mix together flour, salt and sugar to combine. Mix in cubed butter with your hands, pinching and squeezing the butter cubes (or use a pastry blender or food processor) until the largest pieces are the size of lima beans. Drizzle in the water a little at a time, mixing until the dough starts to come together into a mass. You may not need all the water, or you may need to add more.
When dough is starting to hold together but is still somewhat crumbly, transfer it to a lightly floured surface and press and knead it together into a smooth ball. Flatten into disk, wrap in plastic wrap and chill for 1 hour.
While dough chills, heat oven to 400 degrees.
On a rimmed baking sheet, toss together eggplant, 1/4 cup oil, 2 garlic cloves, 1 1/2 teaspoons rosemary, 1 1/2 teaspoons thyme and 1/4 teaspoon salt. On a second rimmed baking sheet, toss together the cherry tomatoes, onion slices, 2 tablespoons oil, 2 garlic cloves, 1 teaspoon rosemary, 1 teaspoon thyme and 1/4 teaspoon salt. On a third rimmed baking sheet (or roasting pan if you don’t have any more baking sheets), toss together zucchini, 2 tablespoons oil, 1 garlic clove, 1/2 teaspoon rosemary, 1/2 teaspoon thyme and a large pinch of salt.
Place all the pans in the oven (or work in batches if they don’t fit at once) and roast until vegetables are browned, tossing every 10 minutes or so; about 35 minutes for onions, tomatoes and zucchini, and 45 minutes for eggplant. Remove from oven and let cool.
On a floured surface, roll out dough to a 12-inch circle, then transfer to a 9-inch pie pan. Crimp edges to make a decorative crust. Use a fork to prick holes in bottom and sides of dough. Chill for 30 minutes.
Raise oven temperature to 425 degrees. Place pie shell on a rimmed baking sheet. Line dough with foil, fill with pie weights and bake for 15 minutes. Remove foil and weights, and continue baking until the dough is just baked through and barely turning golden on the edges, 5 to 10 minutes longer. Transfer to a wire rack to cool. Reduce oven temperature to 375 degrees.
In a medium bowl, beat egg until well mixed, then fold in both cheeses, mayonnaise, a pinch of salt and 1/4 teaspoon pepper.
Scrape all roasted vegetables into a large bowl, add basil, and toss well. Taste and season with more salt and pepper if needed. Spoon mixture into the baked pie shell, then top with cheese mixture. Arrange plum tomato slices on top, if using, and scatter with olives.
Bake until filling is lightly golden, about 30 minutes. Cool for at least 20 minutes before serving warm or at room temperature.