🥧 Savory Mushroom & Leek Gratin – Rich Thanksgiving Side Dish

Ingredients

• • 2 ⅞ large leeks, sliced
• • 2 ⅞ cups mixed mushrooms, sliced
• • 2 ⅞ tablespoons unsalted butter
• • ⅞ cup all-purpose flour
• • 1 ⅞ cups whole milk
• • ⅞ cup grated Gruyère cheese
• • ⅞ cup grated Parmesan cheese
• • Salt and pepper to taste
• • Fresh thyme leaves for garnish

Instructions

1. 1

   In a large skillet, melt 1 tablespoon of butter over medium heat. Add the sliced mushrooms and cook until they release their moisture and start to brown, about 5 minutes. Add the sliced leeks and continue to cook until they are tender and lightly caramelized, about 10 minutes. Season with salt and pepper to taste.

2. 2

   In a medium saucepan, melt the remaining 1 tablespoon of butter over medium heat. Add the flour and whisk to combine, cooking for 1-2 minutes to make a roux. Slowly pour in the milk, whisking continuously to avoid lumps. Bring the mixture to a simmer and cook until it thickens, about 5 minutes. Remove from heat and stir in the Gruyère and Parmesan cheese until melted and smooth. Season with salt and pepper to taste.

3. 3

   Preheat your oven to 375°F (190°C). In a 9x13-inch baking dish, create a layer of the mushroom and leek mixture. Pour some of the béchamel sauce over the top, followed by a sprinkle of additional cheese if desired. Repeat this process until all ingredients are used, ending with a layer of béchamel sauce and cheese on top. Bake for 25-30 minutes, or until the top is golden brown and the gratin is hot and bubbly.