Delicious Tomato, Basil & Parmesan Gratin Recipe

Laura and I have been very fortunate so far this year. Our gardens have produced an astonishing amount of zucchini and yellow squash. The basil is on overload and we’ll likely have enough tomatoes to feed us until September. All year if we jar them correctly. It was with all this in mind that I went on a search for a recipe that would take advantage of some of these vegetables.

Good thing I received my new cookbook from America’s Test Kitchen in a timely manner. It’s titled The Complete Vegetarian Cookbook and it includes enough recipes to keep me busy for at least a year or two. Over 700 of them to be precise. And believe it or not, one of the very first ones is called Summer Vegetable Gratin. Wouldn’t you know, the primary ingredients for this recipe are zucchini, yellow squash, tomato and basil. Just as luck would have it…

The Recipe

I don’t quite know how to say this, but this dish tastes fresh. I believe it has something to do with the basil combining with the Parmesan, tomato and squash. It tastes like summertime. I know that doesn’t make any sense, but I’m at a loss of words of how to otherwise describe it. I think it tastes great.

To prepare this dish, you’ll need some oven time. One of the primary goals is to semi-dehydrate the vegetables. While the onions are caramelized in a skillet, the zucchini, squash and tomato need some drying out in the oven. The recipe from the Test Kitchen suggests using salt to pull out the moisture, but I have an aversion to salting vegetables like this. It’s not good for the heart. Instead, I like to make my slices and lay them on some large baking sheets. A half-hour or so at 300 degrees in the oven does just the trick. I’ll explain more below.

I think this recipe is the gateway to a very popular summer dish. I’m sure a family would absolutely love it as well as would those at a picnic or some other type of get together. There’s nothing wrong with it – and it tastes just right.

Ingredients

Serves: 6

1 Large Zucchini, 1/2 Inch Slices
1 Large Yellow Squash, 1/2 Inch Slices
1 1/2 Pounds Plum Tomatoes (About 6), 1/4 Inch Slices
Regular Table Salt
Ground Black Pepper
Extra-Virgin Olive Oil
Regular Olive Oil
2 Large Sweet Onions, Halved and Sliced Thinly
2 Teaspoons Garlic, Minced
1 Teaspoon Dried Thyme
3 Slices Good Quality Sandwich Bread
1 Cup Parmesan Cheese, Shredded
2 Shallots, Minced
1/2 Cup Fresh Basil, Chopped

Step-by-Step Instructions

I wouldn’t advise rushing through this recipe. It’s important that enough liquid is released from the vegetables. Without that, the end result will be soggy, and no one wants that. Take your time and enjoy. This is a good recipe.

Pre-Heat Your Oven

Go ahead and pre-heat your oven to 350 degrees.

Dehydrate the Squash & Tomato

When the oven is to temperature, spread the slices of zucchini and squash on a large baking sheet and place inside. Do the same for the tomato slices. Let cook for about 30 minutes or until you see the steam coming from the oven slow down and the vegetables begin to soften. When finished, remove the trays from the oven and let cool. Photos of these finished ingredients are below.

Caramelize the Onions

Warm a large skillet over medium heat on your stove top. Add 1 tablespoon of regular olive oil and all the sliced onion to the skillet and cook for approximately 25 minutes, stirring often, or until you see the onions change color to a nice golden brown. When finished, remove the skillet from heat and set aside.

Prepare the Toppings

In a small bowl, add 3 tablespoons of extra-virgin olive oil. Then, add the thyme, garlic, 1/2 teaspoon of salt and a 1/2 teaspoon of ground black pepper. Combine well and set aside, giving time for the flavors to infuse with each other.

After that, break apart the pieces of white bread and add them to your food processor. Run for about 10 seconds or until the bread is finely broken down.

Empty the bread crumbs from the food processor into a large bowl. Add 1 tablespoon of extra-virgin olive oil to them. Also add in the Parmesan cheese and shallots. Combine well.

Arrange Ingredients

In a large 13×9 inch baking dish, spread 1 tablespoon of regular olive oil, making sure it coats the bottom well. Then, carefully arrange the slices of zucchini and squash throughout the entire area. When you use up all of these ingredients and the bottom of the casserole is covered, spoon out half of the oil and garlic mixture and drizzle it over the layer.

Next, spread the caramelized onion across the layer of squash. Be sure the layer is even.

Finally, with a fork, very gently lift each tomato slice from the baking sheet and arrange them on top of the onion. As you can see, we’re simply creating layers for this dish. When that’s completed, drizzle the remaining oil and garlic mixture on top of the tomatoes with a spoon.

Bake the Casserole

Warm your oven to 400 degrees. When it’s to temperature, place the baking dish into it and let cook for about 30 minutes. Since the vegetables were already cooked somewhat, this step doesn’t take as long as it would have, had we just salted the squash and tomatoes.

Add Bread & Cheese Topping

After the first set of ingredients have been cooked in the oven, remove the baking dish and place it on your stove top. Then, spread the breadcrumb and cheese mixture evenly over the top tomato layer.

Increase the oven temperature to 450 degrees and place the baking dish back in for about 10 minutes. Keep a close eye on things to make sure the breadcrumbs don’t burn. If everything goes smoothly, remove the dish from the oven and let cool for another 10 minutes. This is what it should look like:

As you can see, it doesn’t look too terribly different. The bread crumbs are a bit darker and the cheese is melted.

Finally, after the topping has cooled a bit, go ahead and sprinkle the chopped basil over everything.

The Final Dish

Basil is an incredible ingredient and fresh is definitely the way to go. After you cut a few pieces, plate and taste this dish, I think you’ll agree that the basil is what takes it someplace magical. It’s only after the first taste that you’ll notice and enjoy the remaining ingredients. But they’re delicious as well.

——

If you’ve enjoyed today’s post and found it helpful, please share it with a friend. Also, if you’d like to continue reading and would like our posts sent directly to your email inbox, simply sign up for our newsletter. We’ll send each and every post directly to you. Thanks!