Spinach Gratin
Serves 6
5 (10 ounce) boxes of frozen spinach, defrosted
2 tablespoons extra virgin olive oil
6 tablespoons unsalted butter, divided
2 cups diced onions
2 tablespoons minced garlic
1/3 cup all purpose flour
2 1/2 cups whole milk
1/2 cup heavy cream
1 tablespoon kosher salt
1 teaspoon freshly cracked black pepper
1/2 teaspoon freshly grated nutmeg
1 1/4 cup freshly grated parmesan cheese
Preheat the oven to 375 degrees F.
Place the defrosted spinach in a clean kitchen towel and squeeze out as much liquid as you can then transfer to a mixing bowl. Set aside.
Heat the olive oil and 2 tablespoons of butter in a large sauté pan over medium-high heat then sauté the onions for 5-7 minutes, stirring occasionally. Add the garlic and sauté for an additional 2-4 minutes until the garlic is cooked, but not browned. Turn off the heat and transfer the onions and garlic to the defrosted spinach.
Make the roux: Turn the heat back on to medium-high and 3 tablespoons of butter to the sauté pan. Add the flour and stir to fully combine then cook for 1 additional minute. While whisking, slowly pour in the whole milk and cream and cook until the mixture thickens, about 5 minutes. It should be done when the roux coats the back of a wooden spoon. Slowly pour the roux into the bowl with the spinach, onions and garlic. Add the salt, black pepper and 1 cup parmesan cheese.
Coat the inside of a baking dish with the remaining 1 tablespoon of butter and pour the spinach mixture in. Top with the remaining 1/4 cup parmesan cheese and bake for 20-25 minutes until bubbly and browned on top. Remove from the oven, allow to slightly cool and serve warm.