Ingredients

The following ingredients have 4 Servings
  • 4 tablespoons unsalted butter (divided)
  • 3 medium onions (cut in ½ and sliced)
  • 2 pounds zucchini (sliced ¼-inch thick (4-6 small))
  • Kosher salt and freshly cracked black pepper (to taste)
  • ½ pound shiitake mushrooms (sliced)
  • ¼ teaspoon ground nutmeg
  • 2 tablespoons all-purpose flour
  • 1 cup hot milk
  • ¾ cup Panko breadcrumbs
  • 8 ounces Swiss cheese ((or Gruyere))

Instruction

  • Preheat the oven to 400 degrees F.
  • Melt 3 tablespoons of the butter in a very large (12-inch) saute pan and cook the onions over low heat, until tender but not browned; about 20 minutes.
  • Add the zucchini to the pan and season with salt and pepper, to taste. Cover and cook, stirring occasionally, until tender; about 10 minutes.Add the mushrooms to the pan, then season with nutmeg. Cook uncovered for 5 more minutes.Meanwhile, heat the milk until hot, but do not boil or simmer.Stir in the flour; cook for 1 minute. Add the hot milk and cook over low heat for a few minutes, until it begins to thicken and turns into a rich sauce.
  • Pour the mixture into an 8 x 10 inch baking dish. Top the zucchini mixture with the enough Swiss cheese to cover it. Top the cheese with the breadcrumbs and dot with the remaining tablespoon of butter cut into small pieces. 
  • Bake for 20 minutes, or until golden brown and bubbly.