A vegetable gratin might just be the lamest sounding dish ever. Usually gratins are used to drench veggies and starches in loads of cream and cheese so that unsuspecting kids will chow down. Don't get me wrong - a well-made potato gratin can be delicious, if a little heavy. And let's be honest, if it weren't for this recipe being created by Thomas Keller, I wouldn't have given it a second look. But seeing as it is a Thomas Keller recipe and I just bought his Ad Hoc at Home cookbook, how could I fail to give it a try? You will have to excuse me for being a little late to the party as it's now early October, and not summer. But better late than never, especially seeing as the farmer's markets are still full of eggplant, thyme and tomatoes.
I think this was the first time that I have ever heard Alex get excited about a vegetarian recipe and well he should. Like all Keller recipes, this one was very precise and required a number of individual steps and a long prep/cooking time. I adapted the recipe a little to suit myself (although I didn't really do anything to simplify it), including alternating the veggies in layers around the gratin dish, rather than having individual rows of eggplant, then zucchini, then tomato and then squash. I guess I took more of a Ratatouille approach with the alternating rounds of tomato, zucchini, eggplant and squash. I figured that way you would or at least could get all of the vegetables layered together in a single bite. And isn't that better than having one row of the gratin that is only tomato or only squash? I thought so. In the future I probably won't bother broiling the gratin at the end to brown the bread crumbs because our gas oven has a broiler that is permanently set to kill. We barely put the gratin in there for 2 minutes 6-inches away from the heat source and it was verging on burnt. Bad broiler. Anyway, after about 70 minutes the vegetables were cooked perfectly - fork tender, but not so tender that they were falling apart. The lemon thyme and Parmigiano-Reggiano gave the vegetables serious flavor, and the panko mixture gave the dish a wonderful texture. The dish isn't exactly a quick and easy supper, but it is a lovely vegetarian meal that doesn't leave you wanting meat (or carbs), which I consider to be a huge success.
Recipe after the jump!
Ad Hoc's Summer Vegetable Gratin
Adapted from Ad Hoc at Home
By Thomas Keller
2-3 Roma tomatoes, 1 1/2 to 2-inches in diameter, cut into 1/4-inch slices
1 medium yellow squash, trimmed and cut into 1/4-inch slices
1 medium zucchini, trimmed and cut into 1/4-inch slices
1 small eggplant, trimmed and cut into 1/4-inch slices
2 1/2 cups coarsely chopped onions
2 garlic cloves, finely minced
1 tbsp, plus 1 tsp fresh lemon thyme or regular thyme, chopped
1/4 cup evoo, plus more for drizzling
freshly ground black pepper
1/2 cup Parmigiano-Reggiano, grated
1/2 cup panko bread crumbs
Heat canola oil in a large frying pan over medium heat. Reduce the heat to medium-low, add onions. Cook, stirring occasionally, for 20 minutes, adding a large pinch of salt and the minced garlic after 5 minutes. Stir in 1 tbsp thyme.
Combine yellow squash, zucchini and eggplant in a large bowl. Toss with 1/4 cup evoo and season with salt. Drizzle tomatoes with evoo and season with salt and black pepper.
Combine Parm-Reg, panko, and remaining thyme in a small bowl. Set aside.
Spread onion mixture in the bottom of a 13x9x2 baking dish (or any other shallow baking dish). Start layering the vegetables on top of the onion mixture - alternating rounds of tomato, zucchini, eggplant and squash going round the dish and starting along the outside. All layers of the vegetables should be slightly overlapping. Sprinkle the vegetables with the Parm-Reg mixture and sprinkle lightly with salt. Continue making overlapping rows of remaining vegetables until all of the vegetables are gone (or until you have two complete layers of vegetables), topping with remaining Parm-Reg mixture.
Bake gratin until the vegetables are completely tender and offer no resistance when pierced with a knife, roughly 1 to 1 1/2 hours. Remove from oven and allow to rest for 10 minutes. If you want to further brown the breadcrumbs, turn on the broiler. Just before serving, put the gratin under the broiler to brown the top.