Summer Vegetable Gratin

Summer Vegetable Gratin

Another Thomas Keller special from his Ad Hoc at Home cookbook!  This is a healthy, low fat gratin recipe without the heavy cream and cheese.  Layers of summer squash, eggplant, tomatoes, and onions are baked with a sprinkle of bread crumbs and Parmesan cheese to get a light golden crust.

This is a good dish to assemble ahead and then bake before serving.  Keller recommends baking it the day before and then reheating as it will enhance the flavors.  He suggests pairing the vegetable gratin with some Breaded Veal Cutlets, but I preferred something lighter and went with a Whole Roasted Red Snapper.  I also threw in some leftover Tzatziki and Vegetable Couscous that I had made prior for a complete French-Med dinner!


Summer Vegetable Gratin (recipe by Thomas Keller)

Yields: 6 servings


  • 2-3 plum tomatoes, 1½” – 2″ in diameter
  • 1 medium zucchini
  • 1 medium yellow squash (I couldn’t find any in HK so used a lighter colored Chinese zucchini just to mix up the colors of the dish)
  • 1 Japanese eggplant or other small narrow eggplants
  • canola oil
  • 2½ C onions, coarsely chopped
  • 2 garlic cloves, finely grated or minced
  • kosher salt
  • 1 T + 1 tsp fresh thyme, chopped
  • 1/C C extra virgin olive oil, plus more for drizzling
  • freshly ground black pepper
  • ½ C freshly grated Parmigiano-Reggiano
  • ½ C dried bread crumbs


Preheat the oven to 350°F (175°C).

Trim and then slice the vegetables to end up with slices as close to size as possible (¼” thick slices).

sliced eggplant and squash

Heat some canola oil in a large frying pan over medium heat, then reduce to medium-low.  Add the garlic and onions, and season with salt.  Cook without browning, stirring occasionally, until the onions are translucent, about 20 minutes.  Stir in 1 T of the thyme.

Meanwhile, combine the yellow squash, zucchini, and eggplant in a large bowl.  Toss with the olive oil and season with salt.

In a small bowl, combine the Parmesan, bread crumbs, and remaining 1 tsp thyme.

bread crumbs, parmesan

Spread the onion mixture in the bottom of a 13½” x 9½” gratin dish or 13″ round shallow baking dish (I didn’t have any large baking dishes so divided it into two small baking dishes).  Layer the vegetables in the dish, working on the diagonal.  Arrange a layer of overlapping slices of one-third of the zucchini around the outside edge of the dish.  Sprinkle 2-3 T of the cheese mixture over the top.  Make a row of overlapping slices of yellow squash slightly overlapping the zucchini, and sprinkle 2-3 T of the cheese mixture again.  Make a third row with tomatoes and the cheese mixture sprinkle, and finally repeat with a fourth row of eggplant.  Continue making overlapping rows with the remaining vegetables, and sprinkle the top with any remaining cheese mixture and a light dusting of salt.

layer the veggie slices and sprinkle the bread crumb cheese mixture on top

Bake for 1 to 1½ hours until the vegetables are completely tender and can be pierced easily with a knife.  Remove from the oven and allow the gratin to rest for 10 minutes.

Just before serving, turn on the broiler and place the gratin under the broiler to brown the top.


One Response to “Summer Vegetable Gratin”
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  1. […] served the Red Snapper with Vegetable Gratin, Vegetable Couscous, and Tzatziki for a kind of Carribean-French-Mediterranean […]

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