Consider this an ode to the other squash. The quickly forgotten summer squash, often left behind at this time of year as people, including me, find themselves lured toward the oranger, more festive squashes of autumn. But these bright green and yellow varieties want you to know that they, too, can make delicious fall and winter food fare.
Unlike the dishes of summers past, where these bright baby squash were grilled, sauteed or roasted with salt, pepper, a little butter, and a sprinkling of lemon juice, this summer squash gratin is anything but summery. It’s hearty, rich, and creamy, but, despite the cream sauce, it doesn’t leave you feeling weighed down. Somehow, the buttery summer squash actually make it taste light, while the walnut topping adds a nice crunch … as long as you don’t use pre-toasted nuts (I learned the hard way; you can see in the pictures that my walnuts are extra toasty, which is decidedly less delicious). Couscous thickens it up a bit, making it more of a meal than a mere side dish, although you could certainly omit the couscous and decrease the amount of bechamel to make it a true side dish.
I like to serve it with a dollop of marinara sauce, just for some added color and a punch of fresh flavor. I thought about layering both tomato and cream sauce in the gratin itself, but as it would all melt together in the oven, the bright tomato flavor that I enjoy manually adding to every two or three bites of creamy gratin would be lost by a fully combined tomato-cream sauce.
Summer Squash Gratin
1 1/2 lbs. (24 oz.) summer squash, thinly sliced
1 tsp. salt, plus more to taste
1 Tbsp. olive oil
1 clove garlic, minced
1/2 small onion, finely diced
ground black pepper to taste
1 1/2 c. Cheesy Herb Bechamel (recipe below)
1/2 c. couscous
1 Tbsp. marjoram (can substitute oregano)
1/4 c. finely grated Parmesan, packed
1/4 to 1/2 c. walnuts, chopped (untoasted! I forgot mine were pre-toasted and they burned!)
fresh marinara sauce for serving (optional, but I recommend it, especially if you’re serving this as a main course)
Preheat oven to 375F. Lightly oil a gratin dish. Toss sliced squash with 1 tsp. salt, and set in colander to drain for a few minutes. Then, using a towel or paper towel, squeeze moisture out of squash.
Heat olive oil in large skillet over medium heat. Saute onions and garlic until translucent, about 3 minutes. Add squash slices, and stirring occasionally, saute until pan is dry and squash has begun to brown. Season with salt and pepper to taste.
Combine couscous, squash, half the Cheesy Herb Bechamel, and marjoram, and pour into gratin dish in even layers, smoothing the top. Add Parmesan to remaining bechamel sauce, and spread it over the top. Top with untoasted walnuts.
Bake until bubbly, about 17 to 22 minutes (check 7 minutes before done to make sure walnuts aren’t getting too dark too fast, but if they are, cover with foil to prevent burning). Broil for 2 minutes, until top is golden. Serve hot with a dollop of fresh tomato sauce.
Cheesy Herbed Bechamel
Makes 2 cups
2 c. milk (I used 1%)
1 tsp. thyme
1 garlic clove, minced
3 Tbsp. butter
3 Tbsp. flour
salt and pepper to taste
1/4 tsp. nutmeg
3 Tbsp. Dijon mustard
1/2 c. Parmesan, finely grated
In small pan or microwavable bowl, heat milk, thyme, and garlic until milk is hot but not boiling. Allow to steep for a few minutes while you prepare the roux, which will thicken the cream sauce.
Meanwhile, in a small pot over medium heat, melt butter. Add flour, whisking constantly for about two minutes to form a roux. Slowly, whisk in the aromatic milk, and whisk until thickened. Stir until sauce comes to a boil, then decrease heat to low. Cook for 10 minutes, stirring occasionally. Season with salt, pepper, and nutmeg. Remove from heat, and stir in Dijon mustard and Parmesan. Set aside until ready to use in the gratin.