Continue After Advertisement
Ingredients
-
6 tablespoons
butter, divided
-
2
medium red onions, thinly sliced
-
2 pounds
delicata squash, cut in half lengthwise, seeds removed, then cut into 1/2 inch thick moons
-
1 1/2 teaspoons
salt, divided
-
1 1/4 pounds
tomatoes, sliced thin
-
1/2 cup
vegetable broth
-
1/2 cup
all purpose flour
-
1 1/4 cups
whole milk
-
1 tablespoon
Dijon mustard
-
2 cups
gruyere cheese, grated
-
2 tablespoons
flat-leaf parsley, chopped
Directions
-
Preheat oven to 400F.
-
In a heavy bottomed skillet, melt 4 tablespoons butter over medium heat. Add red onions and cook for about 2 minutes, until they start to soften. Add squash and ½ teaspoon salt. Cook until squash starts to brown, about 5 minutes. Pour in stock, bring to a simmer, reduce heat and cook for about 5 more minutes.
-
Meanwhile, make the sauce. In a small saucepan, melt remaining 2 tablespoons of butter. Remove from heat and whisk in flour until a thick paste forms. Slowly add milk, whisking constantly. Return saucepan to heat and continue to whisk until mixture starts to thicken, about 3 minutes. Remove from heat and stir in 1 teaspoon salt, Dijon mustard, and half of the cheese.
-
Transfer squash and onions to a 9 x 13 inch baking dish. Add tomatoes, tucking them all around the squash and between layers, so their evenly spread throughout the baking dish. Pour sauce on top and use a wooden spoon to mix throughout. Top gratin with remaining cheese and parsley.
-
Bake for 15 minutes until squash is soft and cooked through. Turn broiler on high and finish under the broiler for 5 minutes, so cheese starts to brown. Let cool for 10 minutes before serving.
See what other Food52ers are saying.