Use up in-season squash with this quick gratin. It’s topped with a creamy Mornay sauce, a classic bèchamel plus Gruyère cheese.
Prep Time::15 mins
Cook Time::15 mins
Total Time::30 mins
Servings::4
Ingredients
1/2 cup water
3/4 cup thinly sliced Vidalia onion
8 ounces zucchini, sliced 1/4-inch thick
8 ounces yellow squash, sliced 1/4-inch thick
1 1/2 teaspoons chopped fresh oregano
1/2 teaspoon salt, divided
1 tablespoon olive oil
1 tablespoon all-purpose flour
1/8 teaspoon freshly ground black pepper
2/3 cup whole milk
1/2 cup shredded Gruyere cheese
Directions
Set oven rack 6 inches from heat source; preheat broiler. Bring water to a boil in a large skillet; add onion, zucchini, and yellow squash. Reduce heat; simmer, covered, until tender, 7 to 9 minutes. Drain. Transfer to a 1-quart baking dish. Sprinkle with oregano and 1/4 teaspoon salt.
In a small saucepan, heat oil over medium heat. Whisk in flour, pepper, and remaining 1/4 teaspoon salt; cook until foaming, then whisk in milk until thickened, about 2 minutes. Stir in Gruyère cheese until melted; pour over vegetable mixture.
Broil until browned, about 2 minutes. Sprinkle with more oregano and pepper.